Effect of Surface Residue Management under Minimum Tillage on Crop yield and Soil Quality Indices after 6 years in Sorghum (Sorghum bicolor (L.) Moench) - Cowpea (Vigna unguiculata) System in Rainfed Alfisols

Not AvailableABSTRACT: This experiment was conducted in rainfed semi-arid tropical Alfisol at Hayathnagar Research Farm of Central Research Institute for Dryland Agriculture, Hyderabad, India, during the period 2005 to 2010 to study the long-term effect of varying levels of surface residue application under minimum tillage on crop yields and soil quality in sorghum-cowpea system. The experiment was conducted in a randomized block design with minimum tillage (MT) as main block. The experimental treatments comprised of application of four levels of dry sorghum residues (@ 0, 2, 4 and 6 t/ha) as surface application. After 6th year of the experimentation, the pooled mean sorghum grain yield varied from 1607 to 1819 kg/ha across the treatments and was significantly influenced by the residue application. The percent increase in pooled grain yields with residue application @ 2, 4 and 6 t/ha was to the extent of 5, 9 and 13.0% respectively over the control (no residue application). Similarly, the pooled mean cowpea yield varied from 335 to 541 kg/ ha across the treatments and was significantly influenced by the residue application. The percent increase in cowpea grain yield with @ 2, 4 and 6 t/ha was to the extent of 28, 61 and 45% respectively no residue application. Significantly higher organic carbon (6.80 g/kg) content was recorded with the application of sorghum stover @ 6 t/ha which was 55.89% higher compared to control (4.36 g/ kg). The increase in available N with the application of 6t and 4t crop residue was to the extent of 19.5 and 28% respectively while significantly higher contents of soil available P (10.67 kg/ha) and K (288.8 kg/ha) were observed with application of sorghum residue @ 4 t/ha. Among the biological properties, significantly higher microbial biomass carbon (MBC) and dehydrogenase activity (DHA) were recorded with the application of sorghum stover @ 4 t/ha. Besides reducing the bulk density, the application of residues had a significant influence on the mean weight diameter (MWD) of the soil aggregates. The highest overall soil quality index (SQI: 9.58) was observed with the residue application @ 6 t/ha. A significant positive relationship was observed between SQI and pooled cowpea seed yield (R2=0.82) and pooled sorghum grain yield (R2=0.69).Not Availabl

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Not AvailableA long term study was conducted in the rainfed Inceptisol soils at All India Coordinated Research Project (AICRPDA), Rakhdhiansar (J&K) from 1998 to 2005. The main objectives of the present study were to quantify the long-term effects of conjunctive nutrient management on soil quality parameters, to identify the key indicators of soil quality using data redundancy technique and to compute integrated soil quality Index (SQI) and relative soil quality Index (RSQI) as influenced by long term INM treatments in Hill and mountainous Inceptisol soils in Northern India under maize - black gram system. Six INM treatments were considered for the study viz., T1: Control; T2: 100% N (inorganic); T3: 50% N (inorganic); T4: 25 kg N (compost); T5: 15 kg N (compost) + 10 kg N (inorganic) and T6: 15 kg N (compost) + 20 kg N (inorganic). After eight years of study, results revealed that the soil organic carbon was significantly higher with the long term application of 25 kg N (compost) (5.20 g kg-1) and 15 kg N (compost) + 20 kg N (inorganic) (5.19 g kg-1). Among the macronutrients, available N and P were significantly influenced by the integrated nutrient management treatments while available K was not influenced much. Significantly highest available N content of 156.5 kg ha-1 was observed with the application of 25 kg N through compost and significantly highest available P of 36.7 kg ha-1 was recorded with the application of 15 kg N (compost) + 20 kg N (inorganic). Among the secondary nutrients, irrespective of their significant influence, the content of both exchangeable Ca and Mg, varied from 2.47 to 3.76 cmol kg-1 and 0.43 to 0.52 cmol kg-1 respectively. Available S, being significantly influenced by the nutrient management treatments was observed to be highest under application of 25 kg N through compost (22.7 kg ha-1). Among the micronutrients, available Zn and B were conspicuously influenced by the management treatments while Fe, Cu and Mn were not influenced. Among the biological parameters viz., DHA, microbial biomass carbon (MBC) as well as labile carbon were significantly influenced by the management treatments. Application of 15 kg N (compost) + 20 kg N (inorganic) recorded significantly highest DHA (2.79 μg TPF hr-1g-1) as well as labile carbon (355.0 μg g-1 of soil) while application of 25 kg N (compost) recorded significantly highest MBC of 162.0 μg g-1 of soil. Among the physical soil quality parameters, both bulk density as well as mean weight diameter were significantly influenced by the management treatments. Soil quality assessment studies indicated that available N, exchangeable Ca, available Zn, & B, MBC and bulk density were found to be the key indicators of soil quality under maize-black gram. Among all the treatments practiced under maize-black gram system, application of 25 kg N through compost had significantly highest RSQI of 0.97 which was at par with application of 15 kg N (compost) + 20 kg N (inorganic) (0.94) ( P=0.05). The order of performance of the treatments in terms of soil quality was : 25 kg N (compost) ( 0.97) >15 kg N (compost) + 10 kg N (inorganic) (0.87) > T 100% N (inorganic) (0.83) > 50% N (inorganic) (0.81) > Control ( 0.63).Not Availabl

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Not AvailableLong-term fertilizer experiments were conducted on cotton (Gossypium hirsutum) for 21 years with eight fertilizer treatments in a fixed site during 1987–2007 to identify an efficient treatment to ensure maximum yield, greater sustainability, monetary returns, rainwater-use efficiency, and soil fertility over years. The results indicated that the yield was significantly influenced by fertilizer treatments in all years except 1987 1988, and 1994. The mean cotton yield ranged from 492 kg ha−1 under the control to 805 kg ha−1 under 25 kg nitrogen (N) [farmyard manure (FYM)] + 25 kg N (urea) + 25 kg phosphorus (P) ha−1. Among the nutrients, soil N buildup was observed with all treatments, whereas application of 25 kg N + 12.5 kg P ha−1 exhibited increase in P status. Interestingly, depletion of potassium (K) was recorded under all the fertilizer treatments as there was no K application in any of the treatments. An increase in soil N and P increased the plant N and P uptake respectively. Using relationships of different variables, principal component (PC) analysis technique was used for assessing the efficiency of treatments. In all the treatments, five PCs were found significant that explained the variability in the data of variables. The PC model of 25 kg N (FYM) +25 kg N (urea) + 25 kg P ha−1 explained maximum variability of 79.6% compared to other treatments. The treatment-wise PC scores were determined and used in developing yield prediction models and measurement of sustainability yield index (SYI). The SYI ranged from 44.4% in control to 72.7% in 25 kg N (FYM) + 25 kg N (urea) + 25 kg P ha−1, which attained a mean cotton yield of 805 kg ha−1 over years. Application of 25 kg N (FYM) + 25 kg N (urea) + 25 kg P ha−1 was significantly superior in recording maximum rainwater-use efficiency (1.13 kg ha−1 mm−1) and SYI (30.5%).This treatment also gave maximum gross returns of Rs. 30272 ha−1 with benefit–costratio of 1.60 and maintained maximum organic carbon and available N, P, and K in soil over years. These findings are extendable to cotton grown under similar soil and agroclimatic conditions in any part of the world.Not Availabl

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Not AvailableSoils in the hot, arid topical regions are low in organic matter and fertility and are structurally poor. Consequently, these soils suffer on account of poor physical, chemical, and biological soil quality traits, leading to miserably low crop yields. Long-term use of conjunctive nutrient management and conservation tillage practices may have a profound effect on improving the quality of these soils. Therefore, the objective of this study was to identify the key soil quality indicators, indices, and the best soiland nutrient-management practices that can improve soil quality on long-term basis for enhanced productivity under a pearl millet–based system. The studies were conducted for the Hissar Centre of All-India Coordinated Research Project at the Central Research Institute for Dryland Agriculture, Hyderabad. Conjunctive nutrient-use treatments and conservation tillage significantly influenced the majority of the soil quality parameters in both the experiments. In experiment 1, the key soil quality indicators that significantly contributed to soil quality in a rainfed pearl millet–mung bean system were available nitrogen (N, 35%), available zinc (Zn; 35%), available copper (Cu; 10%), pH (10%), available potassium (K; 5%), and dehydrogenase assay (5%). The three best conjunctive nutrient-use treatments in terms of soil quality indices (SQI) were T3, 25 kg N (compost) (1.52) >T6, 15 kg N (compost) + 10 kg N (inorganic) + biofertilizer (1.49) >T5, 15 kg N (compost) + 10 kg N (green leaf manure) (1.47). In experiment 2, under a rainfed pearl millet system, the key indicators and their percentage contributions were electrical conductivity (15%), available N (19%), exchangeable magnesium (Mg; 18%), available manganese (Mn; 13%), dehydrogenase assay (19%), microbial biomass carbon (C; 5%), and bulk density (11%). The three best tillage +nutrient treatments identified from the viewpoint of soil quality were T1, conventional tillage (CT) + two intercultures (IC) + 100% N (organic source/compost) (1.74) >T3, CT + two IC + 100% N (inorganic source) (1.74) >T4, low tillage + two IC + 100% N (organic source/compost) (1.70). The findings of the present study as well as the state-of-the-art methodology adopted could be of much interest and use to the future researchers including students, land managers, state agricultural officers, growers/farmers, and all other associated stakeholders. The prediction function developed between long-term pearl millet crop yields (y) and soil quality indices (x) in this study could be of much use in predicting the crop yields with a given change in soil quality index under similar situations.Not Availabl