MOKGADI MIZEN RAMOROKA DISSERTATION SUBMITTED IN FULFILMENT OF THE REQUIREMENTS FOR THE DEGREE MASTER OF AGRICULTURAL MANAGEMENT (AGRONOMY)

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1 GRAIN YIELD, GRAVIMETRIC MOISTURE CONTENT, DRY MATTER ACCUMULATION AND CHLOROPHYLL PRODUCTION IN MAIZE-LEGUME INTERCROP UNDER MINIMUM AND CONVENTIONAL TILLAGE SYSTEMS MOKGADI MIZEN RAMOROKA DISSERTATION SUBMITTED IN FULFILMENT OF THE REQUIREMENTS FOR THE DEGREE MASTER OF AGRICULTURAL MANAGEMENT (AGRONOMY) DEPARTMENT OF PLANT PRODUCTION, FACULTY OF SCIENCE AND AGRICULTURE, AT THE UNIVERSITY OF LIMPOPO, SOUTH AFRICA AUGUST 28 SUPERVISOR: PROF. K. K. AYISI Tble of contents

2 LIST OF TABLES... 3 LIST OF FIGURES... 4 DISSERTATION ABSTRACT... 6 CHAPTER I... 8 GENERAL INTRODUCTION AND LITERATURE REVIEW... 9 CHAPTER INTRODUCTION MATERIALS AND METHODS Experimentl Design Agronomic chrcteristics Dt Anlysis RESULTS AND DISCUSSION Site chrcteristics Initil soil condition Wether Grin yield Mize Legumes Agronomic Chrcteristics CONCLUSIONS CHAPTER INTRODUCTION MATERIALS AND METHODS Grvimetric moisture Dry mtter Chlorophyll redings... 5 RESULTS AND DISCUSSIONS Grvimetric moisture Chlorophyll Production Dry mtter production Mize Legumes CONCLUSION CONCLUSION AND RECOMMENDATIONS Mjor study finding Recommendtions... 8 REFERENCES DISSERTATION APPENDIX Tble 1. Response of mize grin yield to tillge systems t Dlmd (22/23 nd 23/24) nd Syferkuil (23/24) Tble 2: Moisture response to tillge system t Syferkuil during 23/24 growing seson Tble3: Moisture response to cropping system t Syferkuil during 23/24 growing seson Tble 4: Moisture response to tillge system t Dlmd during 23/24 growing seson Tble 5: Moisture response to cropping system t Dlmd during 23/24 growing seson... 9 Tble 6: Moisture response to tillge system (Dlmd 22/23) Tble 7: Moisture response to cropping system (Dlmd 22/23)

3 Tble 8: Effect of tillge system on chlorophyll content in the youngest fully expnded lef t Dlmd during 22/23 growing seson Tble 9: Effect of tillge system on chlorophyll content in the lower leves t Dlmd during 22/23 growing seson Tble 1: Effect of cropping system on chlorophyll content in the lower leves t Dlmd during 22/23 growing seson Tble 11: Effect of Crop system on chlorophyll content in the youngest fully expnded lef t Dlmd during 23/24 growing seson Fig 1. Mize yield components s influenced by tillge systems t Dlmd during 22/23 growing seson Fig. 2. Mize yield components s influenced by tillge systems t Dlmd nd Syferkuil during 23/24 growing seson

4 LIST OF TABLES Tble 2.1: Soil form chrcteristics nd their level of suitbility for crop production. Tble 2.2: Initil top nd subsoil nutrient sttus t Dlmd nd Syferkuil during the 22/23 nd 23/24 growing seson. Tble 2.3: Mize yield components s influenced by tillge systems t Dlmd during 22/23 growing seson. Tble 2.4: Mize yield components s influenced by tillge systems t Dlmd during 23/24 growing seson. Tble 2.5: Mize yield components s influenced by tillge systems t Syferkuil during 23/24 growing seson. Tble 2.6: Summry of mize yield components s influenced by tillge systems t Dlmd during 22/23 nd 23/24 nd t Syferkuil during 23/24 growing seson. Tble 2.7: Tsseling, silking nd mturity t Dlmd nd Syferkuil for both growing seson. Tble 2.8: Mize plnt height (m) t Dlmd (22/23 nd 23/24) nd Syferkuil (23/24) s influenced by tillge systems. Tble 3.1: Mize totl Dry mtter ccumultion response to tillge system t Dlmd nd Syferkuil during 22/23 nd 23/24 growing sesons. Tble 3.2: Mize totl Dry mtter ccumultion response to cropping system t Dlmd nd Syferkuil during 22/23 nd 23/24 growing sesons. Tble 3.3: Legume Dry mtter ccumultion to tillge systems t Dlmd nd Syferkuil during 22/23 nd 23/24 growing sesons. Tble 3.4: Legume dry mtter ccumultion response to cropping system t Dlmd nd Syferkuil in ll growing sesons. 3

5 LIST OF FIGURES Fig.2.1: Lnd type mps t Dlmd nd t the University of the Limpopo Experimentl frm t Syferkuil. Fig. 2.2: Minimum nd mximum temperture for Syferkuil during 23/24 growing seson nd for Dlmd during 23/24 nd 22/23 growing seson. Fig. 2.3: Rinfll nd evportion mesurements for Syferkuil during 23/24 growing seson nd Dlmd during 22/23 nd 23/24 growing seson. Fig. 2.4: Mize grin yield t Dlmd nd Syferkuil s influenced by tillge systems during 22/23 nd 23/24 growing seson. Figure 3.1: Moisture response to tillge system t Dlmd during 22/23 growing seson. Figure 3.2: Moisture response to tillge system t Dlmd during 23/24 growing seson. Figure 3.3: Moisture responses to tillge system t Syferkuil during 23/24 growing seson. Figure 3.4: Moisture response to cropping system t -15 mm depth t Dlmd during 22/23 growing seson. Figure 3.5: Moisture response to cropping system t 15-3 mm depth t Dlmd during 22/23 growing seson. Figure 3.6: Moisture response to cropping system t -15 mm depth t Dlmd during 23/24 growing seson. Figure 3.7: Moisture response to cropping system t 15-3 mm depth t Dlmd during 23/24 growing seson. Figure 3.8: Moisture response to cropping system t -15 mm depth t Syferkuil during 23/24 growing seson. Figure 3.9: Moisture response to cropping system t 15-3 mm depth t Syferkuil during 23/24 growing seson. Figure 3.1: Effect of tillge system on chlorophyll production in youngest lef nd senescence in oldest under CT nd MT. Figure 3.11: Effect of tillge system on chlorophyll production in youngest lef nd senescence in oldest under CT nd MT. Figure 3.12: Effect of tillge system on chlorophyll production in youngest lef nd senescence in oldest under CT nd MT. 4

6 Figure 3.13: Effect of cropping system on chlorophyll content of mize intercropped with the different legumes in the youngest fully expnded lef t Dlmd during 22/23 growing seson. Figure 3.14: Effect of cropping system on chlorophyll content of mize intercropped with the different legumes in the lowest leves t Dlmd during 22/23 growing seson. Figure 3.15: Effect of cropping system on chlorophyll content of mize intercropped with the different legumes in the youngest fully expnded lef t Dlmd during 23/24 growing seson. Figure 3.16: Effect of cropping system on chlorophyll content of mize intercropped with the different legumes in the lowest leves t Dlmd during 23/24 growing seson. Figure 3.17: Effect of cropping system on chlorophyll content of mize intercropped with the different legumes in the youngest fully expnded lef t Syferkuil during 23/24 growing seson. Figure 3.18: Effect of cropping system on chlorophyll content of mize intercropped with the different legumes in the lowest leves t Syferkuil during 23/24 growing seson. 5

7 DISSERTATION ABSTRACT 379 words Mize is dominnt crop in smllholder frming systems in the Limpopo province of South Afric, generlly cultivted s intercrop with grin legumes. The mjor constrint in this cropping system is indequte soil moisture during the growing seson, which lso limits nutrient vilbility to the component crops. The minimum tillge system hs been reported to improve soil moisture vilbility on frmers fields but this hs not yet been verified in n intercropping system in the province. The objective of this study ws to quntify grin yield nd chlorophyll production of intercropped mize, nd to ssess sesonl moisture vilbility under minimum tillge (MT) nd conventionl tillge (CT) systems. Drylnd field experiments were conducted t two loctions in the province nmely, frmer s field t Dlmd in 22/23 nd 23/24 growing sesons nd t the University of Limpopo Experimentl frm t Syferkuil during the 23/24. The experimentl design ws rndomized complete block in split plot rrngement t ll loctions nd sesons. Tillge systems consisting of conventionl tillge nd minimum tillge were the min plot tretments, wheres five different cropping systems nmely, sole mize, nd mize intercrop with cowpe (vriety, Bechun White), cowpe (vriety, Agripers), Lblb ben (vriety, Rongi) nd Velvet ben were ssigned s sub-plot tretments. Mize grin yield in 22/23 t Dlmd ws significntly lower (357 kg/h) under CT reltive to 755kg/h under MT. In 23/24 t Dlmd, grin yields under the two systems were similr, where s t Syferkuil, 15% higher grin yield results ws obtined under MT. Minimum tillge systems resulted in higher number of mize cobs per plnt t Dlmd in both growing sesons nd weight per cob ws 6

8 higher under MT t both loctions nd sesons. At Dlmd, significntly higher soil moisture ws recorded under the MT reltive to the CT depending on depth nd smpling dtes. Chlorophyll content of the youngest fully expnded leves of mize ws generlly higher under MT thn CT, but this ws observed only t the lter stges of plnt growth. The results lso showed tht the rte of senescence (reduced chlorophyll content in older leves) ws higher in mize plnts grown under CT reltive to those under MT. The minimum tillge system hs shown the potentil of being superior system for drylnd mize production, but further reserch involving dditionl loctions is required to scertin this fct. 7

9 CHAPTER I GRAIN YIELD, GRAVIMETRIC MOISTURE CONTENT, DRY MATTER ACCUMULATION AND CHLOROPHYLL PRODUCTION IN MAIZE-LEGUME INTERCROP UNDER MINIMUM AND CONVENTIONAL TILLAGE SYSTEMS. 8

10 GENERAL INTRODUCTION AND LITERATURE REVIEW Mize is the mjor field crop produced by smllholder nd commercil frmers in the Limpopo province. Worldwide, mize is considered stple food crop for mnkind through direct consumption nd indirectly through niml feed (Evns, 1993). The crop originted from Mexico but its production spred quickly round the world. In the Limpopo province, mize is generlly cultivted s intercrop with grin legumes such s cowpe, groundnut nd bmbr nuts. Grin legumes re mjor sources of protein for humns. Intercropping is reported to be one of the most common cropping systems in Afric (Vndemeer, 1992). Some of the dvntges of including grin legumes in cropping systems re, reduced insect nd disese problems, improved soil N vilbility through biologicl nitrogen fixtion by the legumes, nd incresed yield per unit re (Vn Rensburg, 1998). Wter is n importnt constituent of ll living cells, comprising pproximtely 9% of the plnt tissue nd it is medium for proper nutrition nd helthy growth in higher plnts. It is lso required for cellulr ctivities nd mintennce of turgor pressure within cells. The wter in plnt cells keeps the stem upright nd mintins expnded leves so s to receive sunlight for photosynthesis. Hence, ny wter stress during the course of growth constitutes mjor limittion to crop growth nd development nd finl yield (Modib, 22). In South Afric nd Limpopo Province in prticulr, wter is the most limiting production resource mong smllholder frmers engged in field crop production. A dry nd cold winter nd hot summer with few rining dys chrcterize the Limpopo province. Moisture evportes very quickly becuse of the prolonged hot dys. 9

11 Wter sources re generlly scrce, nd griculture s shre of these resources is competing with the domestic nd industril sectors. Agriculture in the Limpopo province is n ctive sector but unless moisture vilbility during crop growth is mintined on frmer s fields, productivity of crops will remin mrginl. Irrigtion is currently the most effective mens of minimizing the constrint of moisture in the cultivtion of crops but this fcility is vilble to only smll proportion of the entire frming popultion in the province. In the production of crop such s mize, moisture stress especilly during the reproductive stge cn led to drstic yield reduction in grin mss. The initil effects of wter stress could occur during the process of germintion nd emergence. Germintion of mize seed, like tht of mny field crops, is very sensitive to wter shortge nd therefore, reduced soil moisture potentil during the germintion process cn limit moisture movement through the seed cot. Wter deficits cn drsticlly reduce the yield from its genetic potentil to zero. In the Limpopo province, losses in crop yields from wter deficits probbly exceed the losses from ll other yield-reducing cuses combined. Low soil nitrogen nd phosphorus content re the next limiting production fctors in the Limpopo province nd South Afric s whole. Nitrogen stress in field crops generlly decreses lef re index, lef re durtion nd crop photosynthesis rte, ll of which leds to lower rdition interception, decresed crop growth rte, nd hence lower grin yield (Brbieri et l., 2). Oloye, (22) found tht n incresed surfce residue under minimum tillge nd the resulting increse in orgnic mtter hd positive effect on corn yield in some but not in ll soil types. Authors further 1

12 indicted tht the increse in surfce residue which results in long term increse of orgnic mtter cn improve soil nd its wter mngement, especilly in soils which re nturlly low in orgnic mtter. Improvement in soil fertility cn be chieved by retining or incorporting crop residues on the field nd supplementing the residues with minerl fertilizers nd lso through the extensive use of leguminous species in rottionl or intercropping systems. Retining crop residues mintins soil fertility through the slow build up of soil orgnic mtter, thereby improving ggregtion nd wter-holding cpcity of soils (Bely et l., 1998). Plnts obtin the bulk of their nitrogen requirements primrily s nitrte nd mmonium from the soil. It is well documented tht the minerl nutrition of plnts is relted, in mny wys directly or indirectly, to soil moisture since the root hirs bsorb dissolved plnt nutrients from the soil solution. Dry soils will obviously result in lower nutrient uptke since the lck of wter reduces nutrient flow nd diffusion. Nitrte is very wter-soluble nd its movement through the soil vi the process of mss flow to plnt roots is reduced when soil moisture is low (Modib, 22). An importnt cropping system tht hs been reported to improve soil moisture vilbility on frmers fields in recent yers is the No-till or reduced tillge system. No-till system is production prctice, where the soil is left undisturbed from hrvest to plnting, except in nrrow seedbed nd for nutrient ppliction (Unger, 1991). No-till system hs been defined s one in which the crop is plnted either without tillge or with just sufficient tillge to llow plcement nd coverge of the seed with soil to llow it to germinte nd emerge (Torbert et l., 21). It hs been further defined s the use of herbicides or other method of killing ll live plnts on the 11

13 surfce of the soil, followed by s little disturbnce of the soil s possible to provide good seed plcement. No-till system leves crop residues on the soil surfce tht reduces the risk of wter nd wind erosion. It lso reduces soil temperture, minimizes soil wter evportion nd hence increses wter vilbility in the soil for crops to grow. The system cn lso reduce the requirements for lbour nd the generl cost of production, which crete the potentil for higher profitbility (Rozs et l., 1999). Currently, the min soil preprtion method in the Limpopo province is by the conventionl tillge system, which involves ploughing followed by disking. Conventionl tillge system is designed to prepre seedbed by eliminting lmost ll the residue tht is left on the soil surfce. The mjor gols of using conventionl tillge system by frmers re to control weeds prior to plnting nd lso to prepre fine seedbed for plcement. Ploughed surfce my lso improve wter infiltrtion for short period of time fter n initil tillge opertion. However, the long-term effects of it re generlly, stedy decline in soil structure, which reduces soil porosity, increses erosion nd hence reduced soil fertility nd productivity. The doption of the no-till system thus hs the potentil of improving soil moisture nd nutrient vilbility during crop growth. However, since the system is reltively new in the Limpopo province, thorough informtion needs to be generted before recommendtions re mde to frmers. Wter resources re generlly scrce, not only in South Afric but in mny other prts of the continent. In South Afric, field crop production is minly crried out summer rin conditions. Rinfed crop production under this climte thus depends strongly on 12

14 both the mount nd distribution of rin. The mount of rinfll is however low nd generlly poorly distributed nd s result, crop yield nd wter use efficiency re low nd vrible (Oweis et l., 2). Although wter is the most bundnt compound on erth, severe to occsionl deficits cn occur during growing seson, which cn hve devstting effects on crop productivity. The wter used per dy by mize generlly increses rpidly from bout 3 dys before silking, peks during fertiliztion nd erly grin fill nd declines therefter (Sprgue nd Dudley, 1988). Smith (1995) lso, reported tht moisture deficit is most dmging during the silking to erly grin fill period, cusing up to 8 percent yield reduction per dy of stress. It is therefore importnt for mize frmers to time the plnting dte so tht the pek wter demnd of the crop coincides with periods of rinfll bundnce. Moisture stress interrupts photosynthesis nd growth until turgor is restored by removl of the stress. Sprgue nd Dudley (1988) pointed out tht, deficit of wter is the single most importnt fctor limiting crop yield on the worldwide scle. Wter use vries with the stge of development of the mize crop. Erly in the growing seson the loss is primrily evportion from soil. As the crop cover increses, trnspirtion becomes n incresingly dominnt fctor. No-till increses the wter vilbility for the crop. By using the no-till system, surfce residue cn be mnged to better conserve soil wter for greter use efficiency by the plnt. Wter loss is different under no-till system, compred with conventionl tillge system (Dniel et l., 1999). Soil wter storge is greter where 13

15 there is no-till compred to stubble mulching or where disk tillge ws used (Unger, 1991). Dniel et l., (1999) reported tht surfce residue potentilly increses infiltrtion of wter into the soil by 25 to 5% under no-till s compred to conventionl tillge system. With conventionl tillge, the soil surfce is unprotected ginst moisture evportion from the beginning of the growing seson until the end. Moisture evportion cn lso be minimized by using cover crops or cerel-legume intercrops. Mize is one of the most suitble crops for cultivtion under no-tillge (Rozs et l., 1999). No-till hs the effect of incresing wter infiltrtion nd storge due to the soil cover nd the undisturbed soil structure s compred to conventionl tillge. Soil cover reduces wter evportion, keeps moisture in the soil, it does not disturb the biologicl ctivities of the soil nd mkes wter vilble to the root system. No-till system cn be effective not only in incresing soil nd wter conservtion, but lso by reducing lbor requirement nd time (Kldivko, 21;Yusuf et l., 1999; Rozs, 1999). Cerel-legume intercrops re common throughout Afric nd lso in the Limpopo Province of South Afric. There re mny dvntges of the system compred to sole cultures. Two min reported dvntges in intercrop system re trnsfer of nitrogen fixed by legumes to the compnion grss species (Brophy nd Heichel, 1989; Egleshm et l., 1981) nd the control of spred of diseses nd pests (Ayisi nd Mposi, 21 nd Mluleke, 24). These dvntges vry over fctors such s plnt species, plnting dtes, soil moisture nd soil fertility. Cerels cn be intercropped 14

16 with legumes, such s cowpe (Vign unguicult), lblb (Lblb purpureus) nd velvet ben (Mucun pruriens) nd other legumes. Intercropping is the growing of two or more crops simultneously on the sme re of lnd, nd this is very common prctice mong smllholder frmers in the Limpopo Province. Intercropping legumes with mize is widely prctised to mximize productivity of lnd, which often increses the totl crop yield bove tht of the sole crops (Clrk nd Myers, 1994). Worldwide, intercropping hs received lot of reserch ttention nd the published informtion is voluminous, but very little hs been published in South Afric. In Afric, up to 9% of legumes re produced s intercrop with mize, millet or sorghum, lthough sole crops of legumes re importnt in some prts of West Afric (Vndemeer, 1992). Cowpe is one of the legumes tht is widely intercropped. In mize/cowpe intercropping system, the two components grow vigorously t bout the sme time nd therefore competition for vilble resources such s solr rdition, moisture nd nutrients is high. Solr rdition is mjor resource determining growth nd yield of component crops in intercropping, especilly when other resources (e.g. wter nd N) re not severely limiting crop growth. As mize plnts become incresingly tller thn cowpe plnts, rdition becomes less vilble to the cowpe. Some cowpe cultivrs my mture before the dverse effect of ssocited mize crop becomes severe nd often erly-mturing cowpe cultivrs re dvntgeous in intercropping (Wtiki et l., 1993). 15

17 Mize cn lso be intercropped with legume cover crops such s velvet ben (Mucun pruriens), cowpe (Vign unguicult) nd lblb (Lblb purpureus). These cover crops re widely promoted s mens of reversing or slowing down the negtive effects of lnduse. Legume cover crops re used s improved fllows nd intercropped in mjor cerel cropping systems (Hrtkp et l., 22). Suggested benefits include reduced soil erosion nd weed competition, s well s improved soil fertility nd structure. Velvet ben is one of the widely used Legume cover crops in mize production systems in Meso Americ, West nd South Afric. It is vigorous, lrge seeded, twining nnul climbing legume with growth cycle of dys, depending on cultivr, plnting dte nd environment (Hrtkp et l., 22). It hs been proven in Zimbbwe tht velvet ben is good nutritious crop s niml feed, both on diry nd beef cttle (Murungweni et l., 22). It hs high level of protein nd ccumultes lrge quntity of dry mtter. Hrtkp et l., (22) reported tht velvet ben cn be introduced into mize production systems in severl rrngements including rottion, rely cropping nd intercropping. The benefits of velvet ben-mize systems my vry with the rrngement of the crop reltive to the mize crop, s well s the climte nd soil environment where it is grown. Lblb ben (Lblb purpureus) is leguminous species tht hs the potentil to be intercropped with mize becuse of its drought tolernce chrcteristics nd bility to produce lrge biomss quickly. Lblb originted in Asi but it is now grown for food throughout the world. The crop is cpble of contributing to the soil N pool through symbiotic fixtion nd its biomss production cn be used s cover cropping nd 16

18 mulching. Preliminry studies conducted on lblb in the province indicted tht the crops could be very ggressive nd competitive nd if not well mnged, could severely suppress mize yields in n intercropping system. One of the benefits of leving plnt residue on the soil surfce is to reduce soil moisture evportion, improve the soil structure nd increse the sttus of soil orgnic mtter. Any tillge method tht leves t lest 2% of the surfce soil covered with crop residue is considered conservtive tillge (Oloye, 22; Kldivko, 21). Oloye, (22) indicted tht residue plcement preceding nd during the growing seson, especilly the mount remining on the soil surfce, ffect ccumultion of soil orgnic mtter, soil erodibility, soil temperture nd soil moisture. They my lso ffect crop growth, mturity nd yield. According to Yusuf et l., (1999), production results under no-till system chnges soil physicl properties nd cn lso increse soil orgnic mtter content. These chnges influence the plnt growth. The chnge cn be detrimentl, neutrl or beneficil for crop growth nd yield depending on soil structure nd texture, climtic fctors such s rinfll nd weed control. Generlly, no-till system hve greter yield when used in soils chrcterized by low orgnic mtter nd poor structure, rther thn in wellstructured soils with high orgnic mtter content. The objective of this study is to determine the growth, moisture nd nitrogen dynmics in mize-legume intercropping s influenced by tillge systems. 17

19 CHAPTER 2 YIELD AND YIELD COMPONENTS OF MAIZE-LEGUME INTERCROP SYSTEM UNDER MINIMUM AND CONVENTIONAL TILLAGE. 18

20 INTRODUCTION Reduced tillge is n importnt soil conservtion system in crop production. To increse nd mintin sustinbility of crop yields in the Limpopo province, vilble wter should be efficiently utilized. Wter is identified s the most widely limiting fctor for crop production in the province. As mize is the most importnt food crop in most res of the province, its yield needs to be mintined or enhnced to ensure food security. Incresed wter use efficiency (WUE) is of gretest interest to frmers when yields re mximized for the vilble wter supply in ech growing seson. High wter use efficiency is of less interest if it is not ssocited with high yields. Economic benefits from incresed wter use efficiency under wter-limiting conditions re usully chieved only if yield is mximized for the vilble wter (Sinclir nd Muchow, 21). WUE, the rtio of grin yield to crop wter use, provide simple mens of ssessing whether yield is limited by wter supply or other fctors (Angus nd vn Herwrden, 21). Wter vilbility plys mjor role in the regultion of seed development nd mturity. Sinclir nd Muchow (21) reported tht crops tht estblish deeper root systems clerly increse crop yields while erlier mturity nd osmotic djustment hd little or no benefit. According to the uthors, incresing soil volume occupied by roots ws the most effective dptive mechnism for incresing growth during succession drying cycle. Crops will be ble to resist drought nd even lodging cused by strong wind. 19

21 Incresed wter storge within the soil profile is necessry to incresing plnt vilble soil wter. Tillge roughens the soil surfce nd breks prt ny soil crust. This leds to incresed wter storge by incresing infiltrtion into soil s well s decresing soil wter losses by evportion compred to residue-covered surfce or n undisturbed surfce. If surfce residue is buried, the soil surfce cn become smooth nd infiltrtion rtes cn decrese for subsequent rin events (Htfield et l., 21). Mny uthors reported tht the grin yield of most cerels (mize, sorghum whet, etc) is higher with reduced tillge, thn with conventionl tillge. More wter is conserved during the fllow periods nd there is deeper wetting of the soil profile in reduced tillge plots. Reduced tillge systems increse the mount of plnt residues left on soil surfce. The presence of residue on the surfce reduced soil wter evportion by 34-5% (Htfield et l., 21). Avilbility of crop residue does not only increse soil wter vilbility but lso increses nitrogen vilbility to plnts nd soil orgnic mtter. Nitrogen is complex prt of the soil system nd its vilbility is ffected by soil type, tillge, N resources (e.g. fertilizer nd mnure) nd crop rottion. Nitrogen is mjor nutrient required by mize crop for higher grin yields nd qulity kernels, nd it is key resource in influencing grin productivity of mize (Brti nd Mitr, 199). Nitrogen is lso dominnt fctor ffecting plnt chlorophyll content, which is generlly relted to yield (Reeves et l., 1993). Inorgnic nitrogen fertilizers re usully pplied to mize s vilble nitrogen is limited in most soils (Sllh, 1991). Nitrogen deficiency in mize my be detrimentl to yield nd qulity, hence must be voided. 2

22 The specific objectives of this study re: 1. To determine the effect of tillge systems on grin yield of mize nd legumes in n intercropping system. 2. To evlute yield components s ffected by the tillge system. 3. To determine the response of gronomic chrcteristics of component crops (flowering, silking, tsselling nd physiologicl mturity) to the tillge systems. 21

23 MATERIALS AND METHODS Field experiments were conducted t two loctions in the Limpopo province nmely, University of the North Experimentl frm t Syferkuil nd t Dlmd on frmer s field. At Dlmd, the experiment ws conducted during the 22/23 nd 23/24 growing sesons, wheres t Syferkuil it ws conducted in 23/24. The lndtypes present t the experimentl site t Dlmd is I132 nd tht of Syferkuil is Bc56. The dominnt soil form t Dlmd is Dundee followed by Vlsrivier, wheres t Syferkuil, the dominnt forms re Hutton nd Binsvlei. The chrcteristic of the soil forms nd their suitbility for crop production is presented in tble 2.1 (Soil clssifiction working group, 1991) Tble 2.1. Soil form chrcteristics nd their level of suitbility for crop production. Soil form Lnd types chrcteristics Suitbility for griculture Hutton This soil type is defined s succession of red-coloured sndy mteril Suitble tht exhibits little or no structure nd is deemed freely drining. The topsoil horizon is Orthic A, which do not show orgnic, humic, vertic or melnic chrcter. This mteril is generlly esy to excvte by hnd or light mechnicl tillge implements. Cly content rnges from 1-25 % nd exhibits modertely low to low permebility. Dundee Soil depth exceeds 12 mm nd cly content of 15-2 %. It is Modertely suitble chrcterised by sesonl perched wter tble which my subject it wterlogging conditions. Binsvlei This soil type is defined s succession of red-coloured sndy mteril underlin by soft ferricrete, nd is indictive of the sesonl occurrence Moderte suitbility of perched wter tbles t reltively shllow depth. Although the upper sndy horizons re generlly esy to excvte by hnd or light mechnicl excvtor, the soft ferricrete occurring t depth my prove difficult to remove, especilly during the drier months. The sndy upper soil lyers my exhibit potentilly compressible nd/or collpsible chrcter. Binsvlei soil lso exhibits modertely low to low permebility, nd the possibility of lterl movement of liquids within the sndy topsoil lyers is there. Vlsriveir Soil depth exceeds 12 mm nd cly content of 15-2 %. It is chrcterised by strongly structured clys which my be difficult to excvte by hnd. The soil is potentilly expnsive which my interfere with proper root development. Modertely suitble The soil type t Dlmd is sndy-cly lom nd t Syferkuil, lomy snd. 22

24 Fig.2.1: Lnd type mps t Dlmd nd t the University of Limpopo Experimentl frm t Syferkuil. Prior to lnd preprtion, representtive soil smples were tken from the two project loctions nd nlyzed for nutrient concentrtion nd texturl clsses. Two spots from the demrcted experimentl site were smpled during 23/24 t both loctions nd one smpling spot during 22/23 t the depth of -3 mm for topsoil nd 3-6 for subsoil (tble 2.2). 23

25 Tempertures t both loctions during the two growing sesons re presented in figure 2.2, wheres rinfll nd evportion re presented in fig 2.3. Lnd preprtion ws done three to two dys before plnting t both loctions in the two growing sesons, using trctor, ripper plnter, disk nd hoes. The experiment ws conducted under drylnd but irrigtion ws pplied t criticl stge of mize when the rinfll ws not received for n extended period. Experimentl Design Rndomized Complete block in Split plot rrngement ws used s n experimentl design with five replictions during 22/23 growing seson nd four replictions in 23/24. Tillge systems consisting of conventionl tillge nd minimum tillge were the min plot tretments wheres five different cropping systems were ssigned s the sub-plot tretments. The sub-plot tretments were, sole mize nd mize intercrop with Bechun White, Agripers, Lblb ben nd Velvet ben. The conventionl tillge system consisted of ploughing, disking nd plnting of mize using conventionl plnter, wheres under the minimum tillge system, mize ws plnted using the ripper plnter without ploughing or disking. Under both tillge systems, n inter row spcing of.9m ws mintined for mize t density of 25 h -1. The legumes were plnted by hnd between the mize t density of 55 plnts h -1 for the Cowpe vrieties, Lblb nd Velvet ben. Mize ws plnted on 11 th December t both loctions nd yers wheres the legumes were plnted pproximtely month lter on the 7 th nd 9 th Jnury 24 t Syferkuil nd Dlmd respectively. Weeding ws done by hnd, twice t both loctions nd sesons during the growing seson. 24

26 Agronomic chrcteristics Dys to flowering, nthesis nd silking of mize were scored when 5% of the plnts on n experimentl unit hd displyed these trits. Physiologicl mturity ws scored when 9% of the mize plnts do not show kernels with milk line. Flowering nd pod stge of legumes ws lso scored t 5 %, while the physiologicl mturity ws scored when 9% pods hd turned brown nd when seeds rttled pods were shken. Yield nd Yield components Grins of both mize nd legumes were hrvested mnully fter physiologicl mturity to determine grin yields. The hrvested re ws 12.6 m 2 nd 18. m 2 t Syferkuil nd Dlmd respectively from the middle rows of ech experimentl unit. The mize cobs were oven dried t 65 C in the lbortory to reduce grin moisture to pproximtely 14%. Mize yield components were determined fter drying s weight per cob, cob number per plot, cob number per plnt, rows per cob, number of kernels per row, number of kernels per cob, 1 seed mss (tble 2.3 ). Yield components of legumes were lso determined fter drying the pods s pods number nd weight per plnt, number of seeds per pod, pods length nd 3 seeds weight. Dt Anlysis Dt were subjected to nlysis of vrince (ANOVA) s outlined by Sttisticl Anlysis System (SAS Institute, 199) to detect sttisticl significnce of tretments. Differences between tretment mens were seprted using the lest significnt difference (LSD) procedure (Gomez nd Gomez, 1984). 25

27 RESULTS AND DISCUSSION Site chrcteristics Initil soil condition The topogrphy t both experimentl loctions ws reltively flt with slope of pproximtely 1 2 %. Nutrient runoff is thus, expected to be miniml t the two sites. The soil ph t the experimentl sites rnged from during the 22/23 growing seson t Dlmd. In 23/24, the ph rnged from nd t Syferkuil nd Dlmd respectively. The ph t the experimentl sites is close to neutrl nd this should enhnce the efficient nutrient ion relese for crop growth nd development. The vilble nitrogen levels in the top nd sub soils rnged from 8-13 mg kg -1 N t Syferkuil nd 1-3 mg kg -1 N t Dlmd in both growing sesons. These N concentrtions correspond pproximtely to kg N h -1 t Syferkuil nd 4-12 kg N h -1 t Dlmd. The soil nitrogen concentrtion is reltively low with the severe deficiency occurring t Dlmd. Supplementry nitrogen s Ure ws pplied s topdress t rte of 3 kg N h -1, three weeks fter plnting t both loctions to improve growth of mize. Phosphorus concentrtion t Syferkuil ws mg P kg -1 compred to 1-24 mg P kg -1 t Dlmd. P concentrtion of 2 mg P kg -1 is usully the recommended minimum stisfctory growth of grin crops. Super phosphte ws pplied t plnting 26

28 t both loctions t rte of 3 kg P h -1 t Dlmd nd 15 kg P h -1 t Syferkuil to improve vilble phosphorous concentrtion in the soil. Potssium concentrtion rnged from mg K kg -1 At Syferkuil, nd from mg K kg -1 nd mg K kg -1 t Dlmd in 22/23 nd 23/24 respectively. The soil potssium concentrtion ws generlly dequte t the two loctions nd hence no supplementry fertilizer ws pplied. The concentrtions of C, Mg, N, Cl nd Zn were dequte t both loctions. Wether The sesonl temperture (mx nd min) ws recorded t both loctions nd the redings re presented in figure 2.2. Syferkuil experienced reltively hotter summer temperture with the mximum temperture of 3.2 o C. The minimum temperture t Syferkuil ws 1.5 o C during winter. At Dlmd the recorded tempertures for two growing sesons were 29.9 o C mximum nd 9.6 o C minimum in 22/23 nd 29.2 o C mximum nd 3.1 minimum in 23/24. The dt suggests the possibility of frost during winter months t both loctions. According to the recorded sesonl rinfll on both loctions, Syferkuil received reltively high rinfll (132.5 mm) during December month when the experiment ws estblished. The totl rinfll of mm ws received t Syferkuil for the entire growing seson. 22 mm nd 48.7 mm rinfll received in Dlmd during 22/23 nd 23/24 respectively during December month. An verge of mm evportion occurred t Syferkuil, mm nd mm t Dlmd 22/23 nd 23/24 respectively. Due to high mount of moisture evportion t both 27

29 loctions supplementry irrigtion ws in plce nd pplied during the criticl stges of drought. Grin yield Mize Mize grin yield ws influenced by the tillge systems t both loctions (Fig. 2.4). At Dlmd in 22/23, mize yielded higher under minimum tillge (MT) compred to conventionl tillge (CT). Mize yields of 357 kg/h nd 755kg/h were obtined from CT nd MT respectively during 22/23 growing seson. During 23/24 growing seson, mize yielded eqully between CT nd MT (Fig. 2.4). Significnt differences were observed t Syferkuil during 23/24. Mize grin yield ws 15.3% higher under MT tillge t Syferkuil compre to CT (Fig. 2.4). Mehdi et l., (1999) lso found tht mize yield is often higher under minimum tillge, becuse MT crops re more efficient t utilizing soil N thn conventionlly tilled crops. Moisture content under the MT ws reserved for longer period due to the undisturbed soil. Root penetrtion ws lso observed to be deeper compred to CT. These fctors might hve contributed to higher mize yield recorded under MT in the present study. According to Vndermeer (1992), in n intercropping system, component crop cn positively modify the growing environment for the benefit of the other crop which cn led to overll yield dvntge in the intercropping system reltive to the sole crop. In this study, lter plnting of legumes, though low growing rte ws observed, suppressed weeds to some extent in the intercrop plots, creting cooler soil conditions which could hve benefited the mize crop (Mluleke, 24) 28

30 Legumes The legumes did not produce ny yield t both loctions except for only few border rows tht flowered. The legumes were plnted month fter mize which my be one of the resons for lck of reproductive growth. Lower rinfll ws received t both loctions nd in both growing seson. At Dlmd hevy hil storm ws experienced during the middle of the growing seson when legumes were only month old cusing significnt dmge to the crops. A legume such s lblb ben hs long growing durtion, rnging from 7-3 dys which my led to filure or dely of flowering during the dry sesons (Mluleke, 24). According to Grdiner nd Crcker (1981), ben-mize intercrop plntings increse light interception nd decrese light reflection s compred with ben solecrop plntings. However, the quntity of light vilble to the ben cnopy is decresed s the mize popultion is incresed. Mize yield components Number of rows per cob At Dlmd in 22/23 the number of rows per cob ws highly influenced by tillge systems. Mize under MT produced cobs with 14 rows compred to 12 under CT (Tble 2.3). Legumes under MT grew tller s compred to CT, therefore the increse on row per cob might be ssocited with the fvourble growing environment creted by from the legumes. During 23/24 growing seson, the mesured prmeter ws non significnt t both loctions (Tbles 2.3 nd 2.4). The lck of 29

31 significnt effect is n indiction tht these prmeters re generlly not environmentlly dependent but rther geneticlly controlled (Modib, 22) Number of kernels per cob Kernel number per cob ws highly significnt t Dlmd in 22/23 with mize under MT producing 31% more kernels per cob thn under CT (Tble 2.3). A similr trend ws observed t Syferkuil during 23/24 growing seson where MT produced significntly higher results thn CT. Kernels per cob ws 14% higher in the MT system thn in the CT system (Tble 2.5). The number of kernels per cob t Dlmd in 23/24 growing seson did not show ny significnt results (Tble 2.3). The best on number of kernels per row ws recorded under minimum tillge compred to the conventionl tillge system except t Dlmd in 23/24. This implies tht the moisture stress ws not high s on the CT. Kernel number is one of the prmeters tht determine the grin yield nd it depends on the rte of grin-filling, durtion nd stress during the reproduction stge (Wng et l., 1999). Number of kernels per row Significntly higher number of kernels per row on mize cob ws recorded under MT compred to CT t the two loctions. The effect ws not significnt t Dlmd in 23/24 (Tble 2.4). MT ws 21% nd 8.6 higher thn CT respectively t During 22/23 growing seson (Tble 2.3). The number of kernels set is more criticl for mize yield nd it is more ffected by environment (Andrde et l., 2). 3

32 Unfvourble environmentl conditions t the period of flowering nd silking cn cuse the reduction in number of kernels per row. Number of cobs per plnt Minimum tillge systems resulted in higher number of mize cobs per plnt t Dlmd during both growing sesons (Tble 2.3 nd 2.4). Number of cobs per plnt ws non significnt t Syferkuil (Tble 2.5). Weight per cob The effect of tillge systems ws significnt t ll loctions in both sesons. Weight per cob recorded under MT ws higher t both loctions nd growing sesons (Tble ). Weight per cob is ssocited with the grin-filling stge. Cobs produced under MT were bigger nd well filled compred to CT production. Similr results of lighter cob weight under CT were observed by Ghffrzdeh et l., (1997). Hundred Seed mss Hundred seed mss ws not ffected by tillge system t both loctions nd in ll growing sesons (Tble ). Agronomic Chrcteristics Tsseling nd Silking Dys to tsseling ws influenced by the tillge system only t Dlmd during 22/23 growing period (Tble 2.7). During 23/24 growing seson, there ws no significnt difference t both loctions (Tble 2.7). Tsseling is n importnt phonologicl stge of crop development becuse it signls chnge of growth of nnul 31

33 crops from vegettive to genertive phse, essentil for yield of most crops (Modib, 22). Dys to silk emergence were significnt highly ffected by tillge t Syferkuil nd not t Dlmd in both sesons (Tble 2.7). Mturity There were no significnt differences for dys to physiologicl mturity between CT nd MT systems for 22/23 nd 23/24 growing sesons t Dlmd. Significnt differences between tillge systems were observed t Syferkuil during 23/24 growing seson. CT system, mize mtured dy erlier thn mize plnted in the MT system (Tble 2.7). Dys to physiologicl mturity did not pper to hve contributed significntly to grin yield differences observed t Syferkuil. Mize plnt height Mize plnt height significntly responded to tillge system t Dlmd (22/23) nd Syferkuil (23/24). The tllest plnts were produced under MT system cross loctions in the two growing sesons (Tble 2.8). Differences in plnt height ws non significnt t Dlmd during 23/24, but tillge nd cropping system interction ws significnt. The height of mize might hve prtly contributed to the higher grin yield observed under minimum tillge system. 32

34 CONCLUSIONS The evportion rte ws much higher thn the rinfll received nd However supplementry irrigtion ws in plce t both loctions to minimise excessive moisture stress on the plnts. Mize grin yield ws generlly higher under the minimum tillge system compred to the conventionl tillge system t the two loctions in both growing sesons. Significntly higher yield components were observed under the minimum tillge system in most of the prmeters studied reltive to the conventionl system. The number of cobs per plnt nd weight per cob in mize were the min yield components ccounting for grin yield increment under the minimum tillge system. Number of rows per cob ws not significnt t both loctions nd this is not surprising s this plnt component is usully geneticlly determined nd not environmentl bsed. Hundred seed mss ws not ffected by tillge system t both loctions nd in ll growing sesons. Dys to physiologicl mturity did not differ between the two tillge systems t Dlmd during both growing sesons, but t Syferkuil, differences were observed. The number of dys to tsseling in mize ws influenced by tillge system only t Syferkuil nd not t Dlmd. No grin yield ws produced in the grin legumes primrily due to severe competition from the mize for moisture nd sunlight. The minimum tillge system hs shown the potentil to be superior system for drylnd mize production but further reserch involving dditionl loctions is required. 33

35 Minimum nd mximum tempertures for Dlmd during 22/23 Mximum nd minimum temprtures for Dlmd during 23/24 Degree celcius S O N D J F M A M J J A Mx Min Degree celcius S O N D J F M A M J J A Mx Min Month Month Minimum nd mximum temperture for Syferkuil during 23/24 Degree celcius S O N D J F M A M J J A Mx Min Month Fig. 2.2: Minimum nd mximum temperture for Syferkuil during 23/24 growing seson nd for Dlmd during 23/24 nd 22/23 growing seson. 34

36 mm Rinfll nd evportion for Dlmd during 22/ Rinfll Evportion mm Rinfll nd evportion for Dlmd during 23/ Rinfll Evportion S O N D J F M A M J Month J A S O N D J F M A M J J A Month Rinfll nd evportion for Syferkuil during 23/ mm Rinfll Evportion S O N D J F M A M J J A Month Fig. 2.3: Rinfll nd evportion mesurements for Syferkuil during 23/24 growing seson nd Dlmd during 22/23 nd 23/24 growing seson. 35

37 35 Mize grin yield (kg/h) b b CT MT 22/23 (Dlmd) 23/24 (Dlmd) 23/24 (Syferkuil) Loction nd growing seson Fig. 2.4: Mize grin yield t Dlmd nd Syferkuil s influenced by tillge systems during 22/23 nd 23/24 growing seson. 36

38 Tble 2.2. Initil top nd subsoil nutrient sttus t Dlmd nd Syferkuil during the 22/23 nd 23/24 growing seson..22/23... Dlmd Syferkuil. 23/24. Smpling point 1 Smpling point 2 Smpling point 1 Smpling point 2 Depth (mm) Depth (mm) Minerls mg kg N P K C Mg N Cl Zn ph % Cly

39 Tble 2.3. Mize yield components s influenced by tillge systems t Dlmd during 22/23 growing seson. Tillge # Cob/ plnt Weight/ cob # Rows/ cob # Kernel/ row # Kernel/ cob 1 seed mss..count...g....count..g.. CT.5b 52b 12b 28b 356b 23 MT Lsd ns Tillge ** ** ** ** ** ns Cropping system ns Ns ns ns Ns ns Tillge*Cropping ** Ns ns ** ** * LSD = Lest significnt difference. Mens followed by the sme letter within column re similr sttisticlly; **= p<.1; *= p<.5; ns = not sttisticlly significnt. CT = Conventionl tillge. MT = Minimum tillge 38

40 Tble 2.4. Mize yield components s influenced by tillge systems t Dlmd during 23/24 growing seson. Tillge # Cob/ plnt Weight/ cob # Rows/ cob # Kernel/ row # Kernel/ cob 1 seed mss..count...g....count..g.. CT.75b 92.9b MT Lsd ns ns Ns ns Tillge ** ** ns ns Ns ns Cropping system ns Ns ns ns Ns ns Tillge*Cropping ns Ns ** * * ns LSD = Lest significnt difference. Mens followed by the sme letter within column re similr sttisticlly; **= p<.1; *= p<.5; ns = not sttisticlly significnt. CT = Conventionl tillge. MT = Minimum tillge. 39

41 Tble 2.5. Mize yield components s influenced by tillge systems t Syferkuil during 23/24 growing seson. Tillge # Cob/ plnt Weight/ cob # Rows/ cob # Kernel/ row # Kernel/ cob 1 seed mss..count...g....count..g.. CT b 13 35b 459b 58 MT Lsd ns 41.3 ns ns Tillge ns ** ns ** ** ns Cropping system ns Ns ns ns Ns ns Tillge*Cropping ns Ns ns ns Ns ns LSD = Lest significnt difference. Mens followed by the sme letter within column re similr sttisticlly; **= p<.1; *= p<.5; ns = not sttisticlly significnt. CT = Conventionl tillge. MT = Minimum tillge 4

42 Tble 2.6. Summry of mize yield components s influenced by tillge systems t Dlmd during 22/23 nd 23/24 nd t Syferkuil during 23/24 growing seson. Tillge # Cob/ plnt Weight/ cob Dlmd 22/23 23/24 # # 1 # Weight/ # # # Kernel/ 1 Kernel/ Kernel/ seed Cob/ cob Rows/ Kernel/ cob seed row cob mss plnt cob row mss # Rows/ cob # Cob/ plnt Weight/ cob # Rows/ cob Syferkuil # Kernel/ row # Kernel/ cob 1 seed mss..count...g....count...g.....cou nt...g....count..g...count...g....count..g CT.5b 52b 12b 28b 356b b MT b b 13 35b 459 b Lsd ns ns ns Ns ns ns 41.3 ns ns Tillge ** ** ** ** ** ns ** ** ns ns Ns ns ns ** ns ** ** ns Cropping system ns ns ns ns ns ns ns Ns ns ns Ns ns ns Ns ns ns ns ns Tillge* Cropping ** ns ns ** ** * ns Ns ** * * ns ns Ns ns ns ns ns 41

43 Tble 2.7. Tsseling, silking nd mturity t Dlmd nd Syferkuil for both growing sesons. Tillge Dlmd Syferkuil 22/23 23/24 23/24 Tsseling Mturity Tsseling Silking Mturity Tsseling Silking Mturity No. dys.. CT b MT 62b b 134 Lsd 1.4 ns ns ns ns ns.5.55 Tillge ns ns ns ns ns ns ** ** Cropping system ns ns ns ns ns ns Ns Ns Tillge*Cropping ns ns ns ns ns ns Ns Ns LSD = Lest significnt difference. Mens followed by the sme letter within column re similr sttisticlly; **= p<.1; *= p<.5; ns = not sttisticlly significnt. CT = Conventionl tillge. MT = Minimum tillge 42

44 Tble 2.8. Mize plnt height (m) t Dlmd (22/23 nd 23/24) nd Syferkuil (23/24) s influenced by tillge systems. Dlmd Syferkuil Tillge 22/23 23/24 23/24.m. CT 1.1b b MT Lsd.9 ns.7 Tillge ** ns ** Cropping system ns ns Ns Tillge*Cropping ns * Ns LSD = Lest significnt difference. Mens followed by the sme letter within column re similr sttisticlly; **= p<.1; *= p<.5; ns = not sttisticlly significnt. CT = Conventionl tillge. MT = Minimum tillge. 43

45 CHAPTER 3 THE RESPONSE OF GRAVIMETRIC SOIL MOISTURE, CHLOROPHYLL CONTENT, NITROGEN UPTAKE AND DRY MATTER ACCUMULATION IN MAIZE TO TILLAGE SYSTEMS 44

46 INTRODUCTION Soil moisture is one of the most limiting fctors to economicl crop production in mny prt of South Afric including the Limpopo Province. Most smllholder frmers in the Limpopo Province hve no ccess to irrigtion fcilities nd hence, crop yields re mrginl nd unrelible even though the soil is good enough for production. Crops such s mize cnnot tolerte drought longer thn one month especilly during the reproductive stge becuse this is the stge where lrge mount of wter is needed (Tbssum, 24). Mngement prctices tht enhnce rin wter infiltrtion nd conservtion re therefore required to improve frmer s productivity nd ensure food security in the province. Tillge prctices my influence soil moisture vilbility throughout the growing seson. Moisture evportion from the soil cn lso be minimized through cropping systems such s intercropping. Although not ll the crops being intercropped will reduce the evportion, cerel-legume or cerel-cover crop combintion is reported to reduce evportion nd further prevent soil nd nutrients erosion (Rozs et l., 1999). Morris et l., 199 indicted tht wter cptured by intercrop differ from wter cptured by the sole crops nd further reported tht wter-utiliztion efficiency by intercrop is greter thn wter-utiliztion efficiency by sole crops, often by more thn 18%. Conventionl tillge prctices re not n efficient soil moisture conservtion technique. Cultivting methods such s minimum tillge cn improve the storge of soil wter better becuse the soil is left undisturbed thereby minimizing evportion losses. Wter runoffs 45