Scientific registration no : 24 Symposium no : 13A Presentation : poster Efficient and economic fertilization of rainfed maizewheat system for its specific yield through soil testing and integrated nutrient management Une fertilisation efficace et économique pour un système pluvial maïs-blé grâce à l analyse de sol dans un mode de conduite intégré SURI V.K., SARITA JHA, VERMA T.S. Department of Soil Science, H.P.Agricultural University, Palampur (H.P.), 176062 India Abstract A field experiment was carried out with maize and wheat on an acid alfisol to find out the extent by which nutrient requirement for various yield targets could be reduced hrough Farm Yard Manure (FHM) application. Identical pattern of treatment effects was observed in two years (1994-96) of experimentation. Treatments comprised of three yiels targets of maize (T30, T40 and T50 q ha-1 grain), soil test based fertilizer dose (STB) and state level fertilizer dose (SLD). Yield targets and STB were evaluated with and without FYM. Highest yields, yield attributing and growth measurements, total NPK uptake, grain protein and benefit cost ratio were given by T50FYM5. FYM involving treatments out performed non-fym one in all abose parameters. Treatments involving FYM appreciably increased the soil available N, P2O5 and K2O, cation exchange capacity, organic carbon, ph and water horlding capacity than these without it and lowered soil bulk density. Yield targeting treatments with FYM enhanced response ration and net returns by 26.4 and 22.0% respectively. FYM contained 77, 57 and 36 kg ha 1 N, P205 and K2O respectively meeting thereby about half (40-60%) of NPK requirement for various targets. Single target of 40 q ha-1 in following wheat was imposed an concerned plots of preceding maize. Maximum increase in wheat yields were recorded in (T50FYM5)M (T40)W. There was NPK economy of 7.0% in wheat succeeding FYM amended maize crop vis-a-vis target of 40 q ha-1. Fertilizer application for targetted yield of crops is situation, location and crop specific and enables to make recommendations for high profit for different levels of production. Little work along this line has been done so for with manure amended rainfed maize under wet temperate condition of India. In the absence of above information, it was not feasible to advise farmers on reduction of fertilizer dose for various yield targets pf maize-wheat systeme under the above situation. Present study was undertaken to generate the above information. 1
MATERIALS AND METHODS A field experiment was conducted during 1994-96 on a Typic Hapludalf at Palampur India (32 6'N, 76 34 E, 1290 m amsl, receiving average annual rainfall of 2500mm) on a soil having ph 5.9, organic carbon 6.8 g kg 1, available N 346, P 10 studied in maize (rainy seasons, 1994 and 1995), residual effect was examined in following wheat (dry seasons, 1994-95 and 1995-96). Treatments in maize comprised three yield targets (T30, T40, and T50 q ha 1 grain), soil test based fertilier dose (STB) and state level fertilizer dose (SLD). Yield targets and STB were evaluated in presend and absence of FYM (5t ha-1 dry weight) with three controls i.e., FYM 5 t ha-1 + N40 kg ha-1 and FYM0N0P0K0. Following fertilizer adjustment equations were used in maize experiment : FN = 5.67T-0.17 SN FP205 = 4.36T-5.26 SP FK20 = 2.29T-0.10 SK Where (i) FN, FP205 and FK2O are fertilzer nutrients (kg ha-1)/ (ii) T = yield target (q ha 1) (iii) SN, SP, and SK are initial soil test values for N, P and K (kg ha-1). Organic arbon content of FYM used in the study was 25.56%, N, P and K contents were 1.54, 0.3 and 0.6 per cent respectively. Based on above information, fertilizer NPK requirements was worked out for various targetting treatments deducting thereby NPK contained in FYM. In wheat, using the following fertilizer adjustment equations, single yield target of 40 q ha-1 was imposed on all yield target/soil test involving plots of preceding maize crop. Objective was to evaluate nutrient economy if any, FN : 4.91T-0.124 SN FP205 : 7.86T-5.16 SP FK2o : 2.44T-0.187 SK No fresh FYM application was made to any plot in wheat crop. Rainfall received during the two rainy seasons was 1685 ans 1300mm respectively whereas it was 286 and 226 mm during the dry seasons. Composite samples of grain and straw (shoot) taken from each plot at crop maturity in both the crops were processed and analysed for toal NPK concentration employing standard methods from which uptake and protein contents were determined. Composite soil samples (0-0.15 m) collected after harvest of maize and wheat were analysed for various properties following standard procedures. RESULTS AND DISCUSSION Maximum net increase over control in grain yield was observed with T50FYM5 (table 1). State level/generalized fertilizer dose and soil test dose aim, at realizing medium/moderate target (40 q ha-1) only. Barring T40FYM5 and T30FYM5, per cent deviation of actual grain yield from targetted yield with and without FYM was +10%. It can be inferred that using fertilizer adjustment equations designed for fertilizer NPK use, grian yield of rainfed maize can be predicted for an integrated nutrient supply system (NPK+FYM 5 t ha-1). Stover yeild followed the trend of grain yield. Maximum increase over control in stover production was given by T50FYM5. Benefit due to FYM incoporation is attributable to improved soil conditions especially the supply of additional plant nutrients and enhanced supply of both native and applied N, P and K (Badiyala and Verma, 1991). Prasad and Prasad (1994) found a considerable saving of N, P 2
and K for irrigated rice. Trend of NPK economy in the current study is similar, even though nutrient savings are much higher i.e. 97, 25 and 30 kg ha-1 of N, P and K respectively. Low grain yield in farmers pratice is attributable to lesser application of N (40 kg ha-1) and no P and K application, apart form the broadcast sowing of the crop. There was no significant difference between T50FYM5 and T50FYM0 in respect of stover yield whereas SLD performed poorly. This trend migh be due to low efficiency of N in the absence of FYM particularly because of high rainfall during the two experimental seasons. Although, fertilizer adjustment equations used in the present study were withoiur the FYM component, yet difference between targetted and actual grain yield was narrow (+10%) in most cases. Added benefit due to improvement in soil physical environment was probably neuralised due to incomplete release of NPK from FYM resulting into a close agreement between anticipated and actual grain yield (table 1). Trend of N, P and K uptake (table 1) was supportive of maize yields. FYM involving targetting treatments increased their uptake respectively by 12.4, 27.7 and 13.01 per cent than those without FYM. Uptake date are justified through same reasoning as given under yields. Maximum increase over control in grain protein content (table 1) was observed in T50FYM5 followed by T50FYM0, T40FYM5 and T30FYM5. it can be observed that targetting treatments with FYM increased maize grain yield by 11.5%, stover yield by 6.3% and protein content by 6.7% over the non-fym counterparts. Highest yielding treatments in following wheat (table 2) were (T50FYM5)M(T40)W and T50FYM0)M(T40)W respectively. This is attributable to wall-known beneficial residual effect of FYM as well as higher root biomass as observed after maize harvest. On an average, 7% less N, P and K had to be applied in FYM involving yield targetted plots of wheat. This is ascribed to superior soil NPK status after maize harvest. Similar trends have been reported by some other workers (Singh and Sekhon, 1978, Suri et al., 1992). Lower yields in case of SLD might be due to lesser NPK efficiency in the absence of FYM. Low performance of farmers' practice is due to low N use in both the above crops, apart from complete absence of P and K. Per cent deviaton of actual wheat grain yield from targetted yield, in most cases was ± 10. Genral trend of N, P and K uptake by weat was supportive of both grain and straw yields (table 2). FYM involving targetting treatments increased NPK uptake respectively by 1, 16 and 29 per cent than those withour FYM. Targetting treatments involving FYM were accompanied by the recovery of significantly higher soil N, P and K than those not involving FYM (table 3) after the harvest of maize as well as wheat. This is attributed to the release of NPK contained in FYM, apart from increased efficiency of applied N, P and K. higher recovery of P in FYM involving treatments is attributable to solubilization of soil phosphorus by organic acids released from FYM. Higher K status partly due to release to K+ from FYM as well as greater capacity of organic colloids to adsorb released K+. prasad and Rokima (1991) reported similar results. Higher amount of soil organic carbon, cation exchange capacity (CEC) and ph was recorded in T50FYM5, T40FYM5 and T30FYM5, T40FYM5 and T30FYM5 (in maize). Respectivve reasoning for this is the addition of carbon due to FYM, its high CEC and the release of Ca, Mg and other poses from it. FYM application also improved the general physical condition of soil as reflected from lesser bulk density (28.2% less than non FYM treatments). It may be inferred that a judicious combined use of NPK and FYM greatly enhance the efficiency of applied fertilizer in rainfed maize wheat sequence. FYM incorporation (5 t ha-1 in rainfed maize decreased fertilizer NPK requirement by nearly 60 per cent for 30 q target, by 50 per cent for 40 q target and by 40 per cent for 50 q target. NPK requirement for 40 q target in following wheat was decreased by 7% due to FYM incorporation in preceding maize 3
crop. Various integrated nutrient management fertilizer dose for targetted yield of rainfed maize-wheat cropping system. REFERENCES Badiyala, D &Verma S.P. 1991 Ind. J. Agron. 38, 498 Prasad, B & Rokima, J. 1991 J. Ind. Soc. Soil Sci. 39, 792 Prasad, B & Prasad J. 1994 Oryza, 3, 140 Singh, B. & Sekhon, G.S. 1978 Annual Report, Dept. Of Soils, PAU, Ludhiana (1977-78) Suri, V.K., Minhas, R.S. & Singh, Ranjodh. 1992. Response of N, P and K by maize using FYM in maize wheat sequence under subtropical rainfed conditions in H.P. National Seminar on Developments in Soil Science. 57 th Con. Ind. Soc. Soil Sci. Keywords : target yield, maize, wheat, integrated nutrient management, soil testing Mots clés : rendement objectif, maïs blé, mode de conduite, analyse de sol. Table 1 : Yield, total NPK uptake by maize after harvest and protein in grain as affected by FYM and NPK application based on yield target concept (average of 2 years) Treatment Yield (kg ha-1) Uptake (kh ha 1) Protein in grain (%) Grain Stover N P K Control 939 3266 28.8 4.2 16.8 6.8 N0P0K0FYM0 1879 5100 83.8 8.7 32.0 8.1 N40P0K0FYM5 2303 6400 110.9 11.7 52.2 8.3 Farmers' pratice SLD 4601 10700 220.9 23.4 99.4 8.6 STB FYM5 4299 12500 216.5 28.3 100.9 8.6 STB FYM0 4554 12800 230.3 34.1 115.9 9.1 T30 FYM5 3650 12000 209.9 37.3 116.5 9.8 T30FYM0 3200 10670 178.0 27.8 95.7 8.7 T40 FYM5 4600 13500 258.2 46.5 134.0 9.8 T40FYM0 4090 12666 223.9 36.5 118.7 9.6 T50 FYM 5 5400 14933 309.9 55.9 171.0 11.4 T50 FYM0 5050 14600 290.3 44.1 159.4 10.6 CD 5% 168 546 8.13 1.3 4.8 0.27 4
Table 2 : Yield, total NPK uptake by weat after harvest and protein in grain as affected by FYM and NPK application bases on yield target concept (average of 2 years) Treatment Yield (kg ha-1) Uptake (kh ha 1) Grain Stover N P K Control 900 2288 29.7 2.7 30.9 N0P0K0FYM0 1100 3110 24.2 3.6 45.8 N40P0K0FYM5 1666 4330 35.8 4.1 47.3 (Farmers' pratice) SLD 2630 6730 60.1 6.1 96.3 STB FYM5 3300 6260 78.5 8.4 105.4 STB FYM0 3066 7630 53.0 7.4 80.5 T30 FYM5 3800 9030 93.8 10.0 134.1 T30FYM0 3366 8530 76.6 9.6 127.8 T40 FYM5 4200 10500 100.6 13.3 109.1 T40FYM0 3943 9760 89.0 10.0 102.1 T50 FYM 5 4566 11230 112.2 12.5 191.1 T50 FYM0 4233 10630 103.9 11.3 106.7 CD 5% 194 489 7.6 1.4 9.4 Table 3 : Soil nutrient status (kg ha-1) after (i) maize harvest (ii) wheat harvest as affected by FYM and NPK application based on yield target concept (average of 2 years) Treatment Maize Wheat N P K N P K Control 121 3 113 96 2 104 N0P0K0FYM0 141 6 122 161 7 141 N40P0K0FYM5 12 6 124 210 7 136 (Farmers' pratice) SLD 256 10 141 280 11 172 STB FYM5 252 8 128 270 9 183 STB FYM0 259 8 133 279 9 142 T30 FYM5 270 11 143 290 12 174 T30FYM0 181 10 139 210 11 170 T40 FYM5 350 11 147 412 12 156 T40FYM0 222 10 143 280 11 143 T50 FYM 5 440 12 186 481 13 155 T50 FYM0 375 10 168 465 11 127 CD 5% 2 0.3 1.0 17 3.5 10.0 5