S.K. Sharma* and N.K. Jain 1

Transcription

1 Indian J. Agric. Res.., 48 (5) , 2014 doi: / x AGRICULTURAL RESEARCH COMMUNICATION CENTRE CHANGE IN SOIL FERTILITY AS INFLUENCED BY VARYING LEVELS OF FERTILIZATION TO KHARIF CROPS AND DIFFERENT WHEAT BASED CROPPING SYSTEMS IN SOUTHERN RAJASTHAN, INDIA S.K. Sharma* and N.K. Jain 1 Rajasthan College of Agriculture, Maharana Pratap University of Agriculture and Technology, Udaipur , India Received: Accepted: ABSTRACT A field experiment was conducted on sandy clay loam soil during kharif and rabi of and There were 3 wheat - based cropping systems (maize -wheat, groundnut - wheat and clusterbean wheat) and 3 treatments (100 % NPK, 100 % NPKS and 100 % NPKSZn) applied to kharif crops, in the main plots and 3 fertilizer (75, 100 and 125 % NPK to wheat) in the sub-plots, was laid out in split plot design with 3 replications. Groundnut wheat cropping system as well as 100 % NPKSZn to kharif crops significantly higher wheat- grain equivalent yield (7118 kg/ha) and (7019 kg/ ha) and available N, P and K of soil. Successive increase in fertility levels up to 125 % NPK significantly increased wheat grain equivalent yield (7063 kg/ha) and available N, P, K and Zn while available S decreased significantly with successive increase in fertility levels up to 125 % NPK. Balance sheet of nutrients indicated maximum deficit of nitrogen ( kg/ha) and sulphur ( kg/ha) in groundnut wheat cropping system and potassium deficit ( kg/ha) in maize wheat cropping system. Maximum deficits of N ( kg/ha) and K ( kg/ha) and positive zinc balance ( kg/ha) were recorded under 100 % NPKSZn. Application of 125 % NPK to wheat recorded maximum positive balance of N ( kg/ha) and P ( kg/ha) but maximum deficits of K ( kg/ ha) and S ( kg/ha), Maximum zinc balance ( kg/ha) was observed under 75% NPK. Groundnut wheat cropping system recorded maximum positive balances of available N ( kg/ha) and P ( kg/ha). Key words: Balanced fertilization, Balance sheet, Cropping systems, Kharif crops, Net change in soil fertility, Nutrient concentration, Wheat. INTRODUCTION Wheat [Triticum aestivum (L.) emend. Fiori and Paol.] is one of the important cereal crop of the country occupying 2.10 million hectares in Rajasthan (GOI, 2009). Presently intensive cropping system is gaining popularity under i rri gated areas of southern Raj ast han. Intensi fi cati on of croppi ng system without balanced fertilization has led to depletion of major as well as micronutrients and hence balanced fertilization is the need of hour. Legumes are reported to have favourable impact on the soil ferti lity and help in i ncreasing the yield of succeeding crop(s) Jain et al. (2005). The inclusion of legume and application of N, P, K, S and Zn for maintaining of soil health vis a vis crop productivity is utmost desired. The fertilizer need of a crop in cropping system mainly depends upon the characteristics of the preceding crops and kind and quantities of manures and fertilizers applied. However, residual NPKS Zn of kharif crop may be utilized by the succeeding crop such as wheat in the rabi season with the background (Sharma and Singh, 2005). Hence, the present investigation was carried out to work out the balance sheet and net change in soil fertility of cropping systems as influenced by balanced fertilization and fertility levels under different wheat-based cropping systems for Southern Rajasthan. * Corresponding author s sandeepk1293@gmail.com 1 Directorate of Groundnut Research, Junagadh (Gujarat) India , navin_jain87@yahoo.com

2 MATERIALS AND METHODS A field experiment was conducted during two consecutive years of and at Instructional Farm, Rajasthan College of Agriculture, Udaipur (Sub-humid Southern Plain and Aravalli Hills Zone), Rajasthan. The calcareous sandy clay loam soil had ph 7.9 available nitrogen ( kg/ ha), sulphur (10.22 kg/ha) and zinc (0.530 ppm), available phosphorus (13.52 kg /ha) and available potassium ( kg /ha). The experiment, consisted of 3 wheat [Triticum aestivum (L.) emend.fiori and Paol.]-based cropping systems namely maize (Zea mays L.)-wheat, groundnut (Arachis hypogaea L.)- wheat and clusterbean (Cyamopsis tetragonoloba (L.) Taubert) wheat] and 3 balanced fertilizer treatments (100 % NPK, 100 % NPKS and 100 % NPKSZn applied to kharif crops) in the main plots and 3 fertility levels (75, 100 and 125 % NPK applied to wheat) in the sub-plots, was laid out in split plot design with 3 replications. The initial soil status is organic carbon (%) 0.42 available N (kg /ha) available P (kg /ha) available K (kg /ha) available S (kg/ha) available Zn (ppm) Fertilizers were applied as per recommendations of the zone. Full doses of N, P, K, S and Zn were applied through urea (after adjusting the amount of N supplied by DAP), di-ammonium phosphate, muriate of potash, gypsum and zinc sulphate, respectively as per the dose under different treatments. Wheat variety (Raj 4037) was of 100 kg/ha. The crop was raised with recommended package of practices. Vol. 48, No. 5, The total uptake at harvest was determined by summing up the uptake by seed/pod/seed and stover/haulm/straw. Nutrient concentrations: The grain/pod/seed and stover/haulm/straw samples were collected and oven dried at 70 C to obtain constant weight. The samples were grinded to fine powder separately through electric grinder for the estimation of N, P, K, S and Zn concentrations as follows: (i) Nitrogen : Nessler s reagent colorimetric method (Lindner, 1944) (ii) Phosphorus : Vanado-molybdo-phosphoric acid (Yellow colour method, Richards, 1968). (iii) Potassium : Flame photometer method (Jackson, 1973). (iv) Sulphur : Tabatabai and Bremner (1970). (v) Zinc : Lindsay and Norvell (1978). RESULTS AND DISCUSSION Wheat-grain equivalent yield: Groundnut wheat cropping system gave significantly higher wheat grain equivalent yield (7118 kg/ha) than clusterbeanwheat and maize-wheat cropping systems during both the years and in pooled analysis (Table 1). Application of 100 % NPKSZn to kharif crops significantly improved the wheat grain equivalent yield averaged over 3 wheat based cropping systems and produced 7.6 and 18.2 per cent over 100 % NPKS and 100 % NPK, respectively on pooled mean basis. Successive increase in fertility levels up Comparison among the cropping systems was done by converting the grain/pod/seed yield into wheat-grain equivalent yield on price basis as per following formula: Economic yield of maize Price of maize/groundnut/ /groundnut/clusterbean x clusterbean(rs/kg) WGEY (kg /ha) = Wheat grain yield (kg/ha) Price of wheat (Rs/kg) At harvest soil samples were collected from each plot analyzed for of available N (Subbiah and Asija 1956), P (Olsen et al.1954), K (Richards 1968), S (Williams and Steinbergs 1959) and Zn (Lindsay and Norvell1978). Nutrient balance sheet was calculated by budgeting of nutrients (N P K S Zn) added as fertilizers and removal by the crops in two years (Jain and Dahama, 2006). The uptake of each nutrient by grain/pod/seed as well as by stover/haulm/straw was computed by the following formula: Nutrient conc. in grain/pod/seed Grain/pod/seed yield or or stover/haulm/straw x stover/haulm/straw yield Nutrient uptake = (kg/ha) 100

3 354 INDIAN JOURNAL OF AGRICULTURAL RESEARCH TABLE 1: Effect of cropping systems, balanced fertilization and fertility levels on wheat- grain equivalent yield (kg/ha) Treatment Pooled Cropping systems Maize - wheat Groundnut - wheat Clusterbean - wheat CD (P= 0.05) Balanced fertilization (Applied to kharif crops) 100 % NPK % NPKS % NPKSZn CD (P= 0.05) Fertility levels (Applied to wheat) 75 % NPK % NPK % NPK CD (P= 0.05) to 125 % NPK to wheat significantly improved the wheat- grain equivalent yield averaged over 3 wheat based cropping systems and registered a mean increase of 20.2 and 8.0 % over 75 and 100 % NPK, respectively. Nutrient concentrations: The analysis of plant parts i.e., grain/ pods/ seed and stover/ haulm/ straw of maize, groundnut and clusterbean at harvest revealed that the application of 100 % NPKSZn signifi cantly i ncreased N, P, K, S and Zn concentrations in grain/ pods/ seed and stover/ haulm/ straw over other balanced fertilization treatments (Table 5 & 6). The marked improvement in N, P, K, S and Zn concentrations in plants seems to be on account of its greater availability in the soil environment and enhanced translocation in plant system. Verma et al., (2006) reported that addition of S + Zn to NPK in balanced proportion at recommended levels enhanced efficiency of each other, thus maintained synergistic interaction. (Table 5 & 6). Soil fertility status: At harvest of wheat available N, P and K in soil were significantly higher when it was grown after groundnut while S status was significantly higher after maize. DTPA Zn did not differ significantly due to preceding crops (Table 2). The decrease in available S after wheat under wheat - groundnut cropping system particularly by groundnut (being oil crop) might be due to more removal of sulphur. Similar findings were also reported by Jawale et al. (1998). Kharif crops fertilized with 100 % NPKSZn significantly improved the available N, P, K, S and TABLE 2: Effect of cropping systems, balanced fertilization and fertility levels on available nutrient contents in soil after harvest of wheat Treatments Available nitrogen Available Available potassium Available Available (kg/ha) phosphorus(kg/ha) (kg/ha) sulphur(kg/ha) zinc(ppm) Cropping systems Maize- wheat Groundnut- wheat Clusterbean- wheat CD (P= 0.05) NS Balanced fertilization (Applied to kharif crops) 100 % NPK % NPKS % NPKSZn CD (P= 0.05) Fertility levels (Applied to wheat) 75 % NPK % NPK % NPK CD (P= 0.05)

4 Zn after harvest of wheat over 100 % NPKS (except S status) and 100 % NPK during both the years (Table 2).This could be partly ascribed to increased availability via profuse growth of preceding crops (maize, groundnut and clusterbean) that add a sizeable amount of root exudates, leaf litter, root parts and other residues which in due course of time improved the fertility of the soil after decomposition, even after raising of succeeding crop.similar findings were also reported by Patidar and Mali (2002). Available N, P, K and Zn increased but S decreased significantly after wheat harvest with each increment of fertility levels up to 125 % NPK (Table 2). This improvement in fertility status (N, P, K and Zn) under 125 % NPK fertilization might be due to cumulative effect of direct addition of higher amount of nutrients (except Zn) through fertilizers, residual effect of preceding legumes. On the other hand, decline in available S with successive increase in fertility levels up to 125 % NPK might be due to more uptake of S by succeeding crop. Results are in agreement with the findings of Auti et al. (1999). Balance sheet of nutrients: Nutrient balance sheet was calculated by budgeting of nutrients (N P K S Zn) added as fertilizers and removal by the crops in two years (Table 3).It showed that maximum deficits of N ( kg/ha) and S ( kg/ha) were found under groundnut wheat cropping system followed by clusterbean wheat particularly for N deficit. The negative N balance for crop sequences involving legumes reflects two processes: (i) The N addition through fertilizer in the sequences involving legume was lower than cereal cereal sequence though the N removal in the former case was invariably higher (ii) the contribution of biological N fixation by legumes was not measured while computing apparent N balance. Earlier reports indicate that legumes may drive 54-70% of their N requirement through biological N fixation (BNF) in most cases (Awonaike et al., 1990). With this consideration, the extent of negative balance under legume systems as computed in this study may be minimized to a level that it would not reflect a depletion of soil N reserve, provided N contributions from BNF are taken into account. These results comprated the findings confirm those of Sharma et al. (2008). The balances of P and Zn were positive under all the cropping systems owing to their less removal by the crops than that applied to them Vol. 48, No. 5, through fertilizers. The negative K balance was observed in all the cropping systems. The maximum deficit of K ( kg/ha) was observed maize wheat cropping system owing to more removal of K by the crops. Similar findings was also reported by Singh et al. (2002). Maximum deficits of N ( kg/ha) and K ( kg/ha) but positive P balance (99.98 kg/ ha) at 100 % NPKSZn may be attributed to higher amount of removal of these nutrients from the soil as a result of higher yields (Table 3). Further, maximum deficit of S at 100 % NPK ( kg/ha) may be attributed to no use of S in this treatment though crops met their requirement from the soil reserve. Similar were the findings of Jain and Dahama (2006). Maximum positive balances of N (17.02 kg/ ha) and P ( kg/ha) at 125 % NPK may be attributed to relatively higher addition of these nutrients compared to their uptake the maximum deficits of K ( kg/ha) and S ( kg/ha) may be attributed to less addition of K and no addition of S compared to their higher uptake (Table 3). Zn balance was by and large same and remained positive at all the levels. Similar were the findings of Jain and Dahama (2006). Net change in soil fertility status: The available nitrogen increased over initial level in all the cropping systems (Table 4). The trend of increase in available nitrogen was in following order: groundnut wheat > clusterbean wheat > maize wheat.this could be due to addition of large amount of nitrogenous fertilizers and N- rich biomass pre dominantly in the form of leaf fall and fixation of atmospheric N by the leguminous. Maximum (4.08 kg/ha) and minimum (0.58 kg/ha) values of available phosphorus were recorded under groundnut wheat and maize wheat cropping systems, respectively. It may be partly due to regular application of phosphatic fertilizer to each crop and partly to solubilizing effect of decomposing organic residue for native soil phosphorus and less removal in proportion to the quantity applied. Kumar et al. (2008) also reported similar findings. Maximum positive balance of available potassium ( kg/ ha) was recorded under clusterbean - wheat cropping system while minimum ( kg/ha) in groundnut wheat cropping system. Negative available S (-1.1 kg/ha) and Zn balances ( ppm) under groundnut wheat

5 356 INDIAN JOURNAL OF AGRICULTURAL RESEARCH TABLE 3: Nutrient removal and balance sheet of nutrients as influenced by wheat- based cropping systems, balanced fertilization and fertility levels Treatments Nutrient Nutrient Uptake (kg/ha) Total Balance applied nutrient in soil (kg/ha) Kharif Rabi Total Kharif Rabi Total removal (kg/ha) (kg/ha) Cropping system: Maize- wheat N P K S Zn Groundnut - wheat N P K S Zn Clusterbean - wheat N P K S Zn Balanced fertilization (Applied to kharif crops) 100 % NPK N P K S Zn % NPKS N P K S Zn % NPKSZn N P K S Zn Fertility levels (Applied to wheat) 75 % NPK N P K S Zn % NPK N P K S Zn % NPK N P K S Zn

6 Vol. 48, No. 5, TABLE 4: Effect of cropping systems, balanced fertilization and fertility levels on net change in soil fertility under different wheat-based cropping systems Treatments Initial Balance in soil Kharif Rabi Kharif Rabi Cropping systems Maize-wheat Available N (kg/ha) Available P (kg/ha) Available K (kg/ha) Available S (kg/ha) Available Zn (ppm) Groundnut-wheat Available N (kg/ha) Available P (kg/ha) Available K (kg/ha) Available S (kg/ha) Available Zn (ppm) Clusterbean -wheat Available N (kg/ha) Available P (kg/ha) Available K (kg/ha) Available S (kg/ha) Available Zn (ppm) Balanced fertilization (Applied to kharif crops) 100 % NPK Available N (kg/ha) Available P (kg/ha) Available K (kg/ha) Available S (kg/ha) Available Zn (ppm) % NPKS Available N (kg/ha) Available P (kg/ha) Available K (kg/ha) Available S (kg/ha) Available Zn (ppm) % NPKSZn Available N (kg/ha) Available P (kg/ha) Available K (kg/ha) Available S (kg/ha) Available Zn (ppm) Fertility levels (Applied to wheat) 75 % NPK Available N (kg/ha) Available P (kg/ha) Available K (kg/ha) Available S (kg/ha) Available Zn (ppm) % NPK Available N (kg/ha) Available P (kg/ha) Available K (kg/ha) Available S (kg/ha) Available Zn (ppm) % NPK Available N (kg/ha) Available P (kg/ha) Available K (kg/ha) Available S (kg/ha) Available Zn (ppm)

7 358 INDIAN JOURNAL OF AGRICULTURAL RESEARCH TABLE 5: Effect of balanced fertilization on Nitrogen and Phosphorus concentration (%) in maize, groundnut and clusterbean Balanced Nitrogen Phosphorus fertilization Maize Groundnut Clusterbean Maize Groundnut Clusterbean Grain Stover Pods Haulm Seed Straw Grain Stover Pods Haulm Seed Straw 100 % NPK % NPKS % NPKSZn S.Em± CD (P= 0.05) TABLE 6: Effect of balanced fertilization on Potassium (%), Sulphur (%) and Zinc (ppm) concentration in maize, groundnut and clusterbean Balanced Potassium Sulphur Zinc fertilization Maize Groundnut Clusterbean Maize Groundnut Clusterbean Maize Groundnut Clusterbean Grain Stover Pods Haulm Seed Straw Grain Stover Pods Haulm Seed Straw Grain Stover Pods Haulm Seed Straw 100 % NPK % NPKS % NPKSZn S.Em± CD (P= 0.05)

8 cropping system may be attributed to higher removal of these nutrients from the soil particularly due to more requirement of S by preceded oilseed crop as well as higher yield of succeeding wheat. Application of 100 % NPKSZn to kharif crops improved the balances of available N (35.99 kg/ha), P (3.25 kg/ha), K (11.33 kg/ha), S (0.46 kg/ ha) and Zn (0.025 ppm) in soil after different wheat based cropping systems (Table 4). It may be attributed to addition of higher amount of organic Vol. 48, No. 5, matter as well as due to increased availability of these nutrients in soil. Positive balances of N (31.75 kg/ha), P (2.68 kg/ha) and K (10.03 kg/ha) at 125 % NPK may be attributed to relatively less removal of NPK in comparison to their addition in the soil (Table 4). Negative available S balance (-1.35 kg/ha) at 125 % NPK may be due to its more removal from the soil without its replenishment through the fertilizers in succeeding crop. While positive available Zn balance. REFERENCES Auti, A.K., Wadile, S.C. and Pawar V.S. (1999). Yield, quality and nutrient removal of wheat (Triticum aestivum) as influenced by levels and sources of fertilizer. Indian Journal of Agronomy 44 (1): Awonaike KO, Kumarasinghe KS and Danso SKA. (1990). Nitrogen fixation and yield of cowpea (Vigna unguiculata) as influenced by cultivar and Brady rhizobium strain. Field Crops Research 24: GOI (2009). Economic Survey Government of India, Department of Economic Affairs, Economic Division, New Delhi, pp: A Jackson, M. L. (1973). Soil Chemical Analysis. Prentice Hall of India Pvt Ltd., New Delhi. Jain, N.K., Singh, S.K. and Poonia, B.L. (2005). Optimization of N, P and K requirement for wheat (Triticum aestivum) grown in sequence with different kharif crops. Research on Crops 6 (1): Jain NK and Dahama AK. (2006). Nutrient use pattern and balance sheet of available nutrients as influenced by phosphorus and zinc fertilization under wheat - pearlmillet cropping system. Journal of Farming Systems Research & Development 12 (1& 2): Jawale SM, Jadhav AS and Patil VG. (1998). Productivity and economics of legumes-winter sorghum (Sorghum bicolor) double cropping systems under tillage practices in western Maharashtra. Indian Journal of Agronomy 43 (3): Kumar S, Singh A, Rana NS and Panwar GS. (2008). Production potential, profitability and sustainability of different wheat (Triticum aestivum) based cropping systems in semi arid region of Uttarakhand. Indian Journal of Agricultural Sciences 78: Linder, R.C. (1944). Rapid analytical method for some of the more common organic substances of plant and soil. Plant Physiology 19: Lindsay W L and Norvell W A. (1978). Development of a DTPA-soil test for zinc, iron, manganese and copper.soil Science Society of American Journal 42 : Olsen SR, Cole CV, Watanabe FS and Dean LA. (1954). Estimation of available phosphorus in soil by extraction with NaHCO 3.Cir. USDA, p: 939. Patidar M and Mali AL. (2002). Residual effect of farmyard manure, fertilizer and biofertilizer on succeeding wheat (Triticum aestivum). Indian Journal of Agronomy 47(1): Richards LA. (1968). Diagnosis and Improvement of Saline and Alkali Soil. U.S.D.A. Hand Book No. 60. Oxford and IBH Publishing Co., New Delhi. Sharma RP, Pathak SK, Haque M and Lal M. (2008). Productivity, profitability and nutrient balance as influenced by diversification of rice (Oriza sativa) wheat (Triticum aestivum) cropping system. Indian Journal of Agronomy 53 (2): Sharma OP and Singh GD. (2005). Effect of sulphur in conjunction with growth substances on productivity of clusterbean (Cyamopsis tetragonoloba) and their residual effect on barley (Hordeum vulgare). Indian Journal of Agronomy 50 (1): Singh SK, Jain NK and Poonia BL. (2002). Production potential and economics of wheat (Triticum aestivum) - based cropping sequences in flood-prone eastern plain zone of Rajasthan. Indian Journal of Agricultural Sciences 72 (4): Subbiah BK and Asija GL (1956). A rapid procedure for the determination of available nitrogen in soils. Current Science 25: Tabatabai, M.A. and Bremner, J.M. (1970). A simple turbidemetric method of determining total sulphur in plant materials. Indian Journal of Agronomy 62: Verma, A., Nepalia, V. and Kanthalia, P.C. (2006). Effect of integrated nutrient supply on growth, yield and nutrient uptake by maize (Zea mays) wheat (Triticum aestivum) cropping system. Indian Journal of Agronomy 51 (1): Williams CH and Steinbergs A. (1959). Soil sulphur fractions as chemical indices for available sulphur in some Australian soil. Australian Journal of Agricultural Research10: