Effect of 46 years' application of fertilizers,FYM and lime on physical,chemical and biological properties of soil under maize–wheat system in an acid Alfisol of northwest Himalayas

Imbalanced fertilizer use with intensive cropping has threatened the sustainability of agroecosystems, especially on acid soils. An understanding of the long-term effects of fertilizers and amendments on soil health is essential for sustaining high crop yields. The effects of application of fertilizers, and amendments for 46 years on soil properties and maize yield in an acid Alfisol were investigated in this study. Ten fertilizer treatments comprising different amounts of NPK fertilizers, farmyard manure (FYM) and lime, and one control, were replicated three times in a randomized block design. At 0–15 cm soil depth, bulk density was least (1.20 t/m³), porosity (49.8%) and water holding capacity (61.7%) were greatest in 100% NPK + FYM, corresponding to the largest organic carbon content (13.93 g/kg). Microbial biomass C and dehydrogenase activity in 100% NPK + FYM were 42% and 13.7% greater than 100% NPK, respectively. Available nutrients were significantly more with 100% NPK + FYM and 100% NPK + lime than control and other fertilizer treatments. At 15–30 cm depth, the effect of various treatments was comparable to the surface layer. Grain yield declined by 55% and 53% in 100% NPK(-S) and 100% NP, respectively, compared with 100% NPK, whereas 100% N as urea alone eventually led to crop failure. Soil porosity recorded the greatest positive correlation (r = .933**), whereas bulk density recorded a negative significant correlation (r = −.942**) with grain yield. The results suggest that integrated use of FYM/lime with chemical fertilizers is a sustainable practice in terms of crop yield and soil health, whereas continuous application of urea alone is detrimental to the soil health.     

Enhancing phosphorus availability,soil organic carbon,maize productivity and farm profitability through biochar and organic–inorganic fertilizers in an irrigated maize agroecosystem under semi‐arid climate

Biochar amendments offer promising potential to improve soil fertility, soil organic carbon (SOC) and crop yields; however, a limited research has explored these benefits of biochar in the arid and semi‐arid regions. This two‐year field study investigated the effects of Acacia tree biomass‐derived biochar, applied at 0 and 10 t ha^?1 rates with farmyard manure (FYM) or poultry manure (PM) and mineral phosphorus (P) fertilizer combinations (100 kg P ha^‐1), on maize (Zea mays L.) productivity, P use efficiency (PUE) and farm profitability. The application of biochar with organic–inorganic P fertilizers significantly increased soil P and SOC contents than the sole organic or inorganic P fertilizers. Addition of biochar and PM as 100% P source resulted in the highest soil P (104% increase over control) and SOC contents (203% higher than control). However, maize productivity and PUE were significantly higher under balanced P fertilizer (50% organic + 50% mineral fertilizer) with biochar and the increase was 110%, 94% and 170% than 100%‐FYM, 100%‐PM and 100% mineral fertilizer, respectively. Maize productivity and yield correlated significantly positively with soil P and SOC contents These positive effects were possibly due to the ability of biochar to improve soil properties, P availability from organic–inorganic fertilizers and SOC which resulted in higher PUE and maize productivity. Despite the significant positive relationship of PUE with net economic returns, biochar incorporation with PM and mineral fertilizer combination was economically profitable, whereas FYM along biochar was not profitable due to short duration of the field experiments.     

Effect of Effective Microorganism Application on Crop Growth,Yield, and Nutrition in Vigna radiata (L.) Wilczek in Different Soil Amendment Systems

A pot experiment was conducted in heat-sterilized soil to evaluate the effect of effective microorganism (EM) application on growth, yield, and nutrient uptake in Vigna radiata (L.) Wilczek var. NIAB Mung 98 in different soil amendment systems. Pot soil was amended with farmyard manure (FYM), Trifolium alexanrinum L. crop residues (TCR), and half (½NPK) and recommended dose (NPK) of chemical fertilizers. The EM application significantly enhanced shoot and root biomass in TCR-amended soil. However, grain yield was significantly enhanced in FYM, TCR, and NPK amendments by 24%, 15%, and 84%, respectively, as a result of EM application. Effect of EM application on nutrient uptake was variable with respect to soil amendment and plant growth stage. In general, EM application enhanced plant nitrogen (N), phosphorus (P), and potassium (K) nutrition in organic amendments while its effect was either negative or insignificant in chemical fertilizer amendments. Effects of EM application on plant nutrient uptake were more pronounced at maturity than at flowering stage.     

Phosphorus Enriched Organic Amendments can Increase Nitrogen Use Efficiency in Wheat

Although nitrogen (N) has the highest requirement for plant growth, N use efficiency (NUE) seldom exceeds 40%. NUE may be improved by integrated application of fertilizer N and enriched organic amendments. The present experiment aimed to test the extent of increase in NUE by integrated application of fertilizer N farmyard manure (FYM) and rock phosphate enriched compost (RPEC). Mineralization kinetics and N release from FYM and RPEC were studied by an incubation experiment. Results revealed that maximum potentially mineralizable N as well as N release (283.9, 186.7 mg kg^?1 soil, respectively) were from RPEC + fertilizer N treated soils, followed by FYM + fertilizer N. Maximum yield, N uptake, and N recovery were obtained from RPEC + fertilizer N treated soils followed by FYM + fertilizer N. Soils treated with RPEC had shown significantly higher dehydrogenase activity than FYM treated soils. Thus, RPEC might increase yield as well as NUE over FYM. N uptake by plant at maximum tillering stage and flowering stage of wheat correlated positively (R² > 0.85) with the decay rate (k and kN₀) parameter of incubation experiment suggesting their relevance as indicators of plant available N.     

Influence of Soil and Fertilizer Nutrients on Sustainability of Rainfed Finger Millet Yield and Soil Fertility in Semi-arid Alfisols

Productivity of rainfed finger millet in semiarid tropical Alfisols is predominantly constrained by erratic rainfall, limited soil moisture, low soil fertility, and less fertilizer use by the poor farmers. In order to identify the efficient nutrient use treatment for ensuring higher yield, higher sustainability, and improved soil fertility, long term field experiments were conducted during 1984 to 2008 in a permanent site under rainfed semi-arid tropical Alfisol at Bangalore in Southern India. The experiment had two blocks—Farm Yard Manure (FYM) and Maize Residue (MR) with 5 fertilizer treatments, namely: control, FYM at 10 t ha^?1, FYM at 10 t ha^?1 + 50% NPK [nitrogen (N), phosphorus (P), potassium (K)], FYM at 10 t ha^?1 + 100% NPK (50 kg N + 50 kg P + 25 kg K ha^?1) and 100% NPK in FYM block; and control, MR at 5 t ha^?1, MR at 5 t ha^?1 + 50% NPK, MR at 5 t ha^?1 + 100% NPK and 100% NPK in MR block. The treatments differed significantly from each other at p < 0.01 level of probability in influencing finger millet grain yield, soil N, P, and K in different years. Application of FYM at 10 t ha^?1 + 100% NPK gave a significantly higher yield ranging from 1821 to 4552 kg ha^?1 with a mean of 3167 kg ha^?1 and variation of 22.7%, while application of maize residue at 5 t ha^?1 + 100% NPK gave a yield of 593 to 4591 kg ha^?1 with a mean of 2518 kg ha^?1 and variation of 39.3% over years. In FYM block, FYM at 10 t ha^?1 + 100% NPK gave a significantly higher organic carbon (0.45%), available N (204 kg ha^?1), available P (68.6 kg ha^?1), and available K (107 kg ha^?1) over years. In maize residue block, application of MR at 5 t ha^?1 + 100% NPK gave a significantly higher organic carbon (0.39%), available soil N (190 kg ha^?1), available soil P (47.5 kg ha^?1), and available soil K (86 kg ha^?1). The regression model (1) of yield as a function of seasonal rainfall, organic carbon, and soil P and K nutrients gave a predictability in the range of 0.19 under FYM at 10 t ha^?1 to 0.51 under 100% NPK in FYM block compared to 0.30 under 100% NPK to 0.67 under MR at 5 t ha^?1 application in MR block. The regression model (2) of yield as a function of seasonal rainfall, soil N, P, and K nutrients gave a predictability in the range of 0.11 under FYM at 10 t ha^?1 to 0.52 under 100% NPK in FYM block compared to 0.18 under MR at 5 t ha^?1 + 50% NPK to 0.60 under MR at 5 t ha^?1 application in MR block. An assessment of yield sustainability under different crop seasonal rainfall situations indicated that FYM at 10 t ha^?1 + 100% NPK was efficient in FYM block with a maximum Sustainability Yield Index (SYI) of 41.4% in <500 mm, 64.7% in 500–750 mm, 60.2% in 750–1000 mm and 60.4% in 1000–1250 mm rainfall, while MR at 5 t ha^?1 + 100% NPK was efficient with SYI of 29.6% in <500 mm, 50.2% in 500–750 mm, 40.6% in 750–1000 mm, and 39.7% in 1000–1250 mm rainfall in semi-arid Alfisols. Thus, the results obtained from these long term studies incurring huge expenditure provide very good conjunctive nutrient use options with good conformity for different rainfall situations of rainfed semiarid tropical Alfisol soils for ensuring higher finger millet yield, maintaining higher SYI, and maintaining improved soil fertility.     

Long-term effect of straw and farmyard manure on soil organic matter in field experiment in the Czech Republic

The effect of long-term (45 years) mineral and organic fertilization on soil organic matter (SOM) quantity (organic C and N content) and quality (hot-water-soluble C content, microbial biomass C content, hydrophobic organic components of SOM, soil enzyme activities) was determined in a field experiment established in Trutnov (North Bohemia, sandy loam, Eutric Cambisol). Six treatments were chosen for investigation: unfertilized control, mineral fertilization (NPK), straw N, farmyard manure (FYM) and straw and FYM completed with mineral NPK. Soil samples were taken from the arable layer (0–20 cm) in spring over the period of 2004–2010. The positive effect of FYM on the total organic C and N content, hot-water-soluble C content and hydrophobic organic components of SOM was more than 50% higher than that of straw and mineral N fertilization. Application of straw N increased microbial biomass C content in soil and generated invertase activity above the level of FYM. Hot-water-soluble C content, hydrophobic organic components of SOM and urease activity were positively correlated with total organic C and N content (R = 0.58–0.98; p < 0.05). Addition of mineral NPK to both the straw and FYM emphasized the effect of organic fertilization in most of monitored characteristics.     

Long-Term Organic Amendment Application Improves Influence on Soil Aggregation,Aggregate Associated Carbon and Carbon Pools under Scented Rice-Potato-Onion Cropping System after the 9th Crop Cycle

A field experiment was conducted to investigate the influence of long-term application of organic manures on aggregate stability, associated carbon concentrations and carbon pools as an important soil-quality parameter under a scented rice-potato-onion cropping system in silt-loam textured soil in Eastern Bihar, India (subtropical climatic condition). Five treatments were used: 1) nitrogen, phosphorus and potassium (NPK) – 100% recommended dose of NPK; 2) NPK+FYM (farmyard manure) – 50%NPK+50% N as FYM; 3) FYM+VC (vermicompost)+ NC (neem cake) – different organic sources each equivalent to 1/3 of the recommended N (FYM +VC +NC); 4) FYM+VC+NC+PSB (phosphate-solubilizing bacteria – different organic sources each equivalent to 1/3 of the recommended N (FYM +VC+NC)+biofertilizers containing N and P carriers (PSB) and 5) FYM+BFN+BM+PSB – 50% N as FYM + biofertilizer for N +Bone meal to substitute P requirement of crops + PSB. The aggregate size distribution (>250 μm) at different soil depths is higher in treatment FYM+VC+NC+PSB and is at par with FYM+VC+NC, followed by FYM+BFN+BM+PSB and NPK+FYM, and the lowest in treatment receiving 100% NPK. The mean carbon concentration in each soil fraction was higher in soil depth 0–10 cm, followed by 10–20 cm and 20–30 cm. The trend of mean weight diameter (MWD) in different treatments was FYM+VC+NC+PSB ≥ FYM+VC+NC > NPK+FYM > FYM+BFN+BM+PSB > NPK. The trend of carbon concentrations in different treatments was FYM+VC+NC+PSB ≥ FYM+VC+NC > FYM+BFN+BM+PSB ≥ NPK+FYM > NPK. Non-labile pool of carbon forms the major portion (60.14%) of the total soil organic carbon (SOC) irrespective of all depths. Bulk density (BD) has a significant role in stabilizing soil aggregates as well as increasing the SOC content in soil. SOC was negatively correlated with BD (r = ?0.870, p = 0.05), MWD (r = ?0.911, p = 0.01) and geometric mean diameter (GMD) (r = ?0.958, p = 0.05) irrespective of depth. This study took further steps toward understanding the enhancing of aggregate stability on organic manures addition for soil quality improvement.     

Critical carbon inputs to maintain soil organic carbon stocks under long‐term finger‐millet (Eleusine coracana [L.] Gaertn.) cropping on Alfisols in semiarid tropical India

Enrichment of soil organic carbon (SOC) stocks through sequestration of atmospheric CO₂ in agricultural soils is important because of its impacts on adaptation to and mitigation of climate change while also improving crop productivity and sustainability. In a long‐term fertility experiment carried out over 27 y under semiarid climatic condition, we evaluated the impact of crop‐residue C inputs through rainfed fingermillet (Eleusine coracana [L.] Gaertn.) cropping, fertilization, and manuring on crop yield sustainability and SOC sequestration in a Alfisol soil profile up to a depth of 1 m and also derived the critical value of C inputs for maintenance of SOC. Five treatments, viz., control, farmyard manure (FYM) 10 Mg ha^–1, recommended dose of NPK (50 : 50 : 25 kg N, P₂O₅, K₂O ha^–1), FYM 10 Mg ha^–1 + 50% recommended dose of NPK, and FYM 10 Mg ha^–1 + 100% recommended dose of NPK imposed in a randomized block design replicated four times. Application of FYM alone or together with mineral fertilizer resulted in a higher C input and consequently built up a higher C stock. After 27 y, higher profile SOC stock (85.7 Mg ha^–1), C build up (35.0%), and C sequestration (15.4 Mg C ha^–1) was observed with the application of 10 Mg FYM ha^–1 along with recommended dose of mineral fertilizer and these were positively correlated with cumulative C input and well reflected in sustainable yield index (SYI). For sustenance of SOC level (zero change due to cropping) a minimum quantity of 1.13 Mg C is required to be added per hectare per annum as inputs. While the control lost C, the application of mineral fertilizer served to maintain the priori C stock. Thus, the application of FYM increased the C stock, an effect which was even enhanced by additional amendment of mineral fertilizer. We conclude that organic amendments contribute to C sequestration counteracting climate change and at the same time improve soil fertility in the semiarid regions of India resulting in higher and more stable yields.     

Long‐term fertilization impacts on corn yields and soil organic matter on a clay‐loam soil in Northeast China

A long‐term fertilization experiment with monoculture corn (Zea mays L.) was established in 1980 on a clay‐loam soil (Black Soil in Chinese Soil Classification and Typic Halpudoll in USDA Soil Taxonomy) at Gongzhuling, Jilin Province, China. The experiment aimed to study the sustainability of grain‐corn production on this soil type with eight different nitrogen (N)‐, phosphorus (P)‐, and potassium (K)–mineral fertilizer combinations and three levels (0, 30, and 60 Mg ha^–1 y^–1) of farmyard manure (FYM). On average, FYM additions produced higher grain yields (7.78 and 8.03 Mg ha^–1) compared to the FYM0 (no farmyard application) treatments (5.67 Mg ha^–1). The application of N fertilizer (solely or in various combinations with P and K) in the FYM0 treatment resulted in substantial grain‐yield increases compared to the FYM0 control treatment (3.56 Mg ha^–1). However, the use of NP or NK did not yield in any significant additional effect on the corn yield compared to the use of N alone. The treatments involving P, K, and PK fertilizers resulted in an average 24% increase in yield over the FYM0 control. Over all FYM treatments, the effect of fertilization on corn yield was NPK > NP = NK = N > PK = P > K = control. Farmyard‐manure additions for 25 y increased soil organic‐matter (SOM) content by 3.8 g kg^–1 (13.6%) in the FYM1 treatments and by 7.8 g kg^–1 (27.8%) in the FYM2 treatments, compared to a 3.2 g kg^–1 decrease (11.4%) in the FYM0 treatments. Overall, the results suggest that mineral fertilizers can maintain high yields, but a combination of mineral fertilizers plus farmyard manure are needed to enhance soil organic‐matter levels in this soil type.     

Soil amendments and seed priming influence nutrients uptake,soil properties,yield and yield components of wheat (Triticum aestivum L.) in alkali soils

The effects of soil amendments [i.e., control, gypsum, farmyard manure (FYM), and gypsum?+?FYM] and seed priming (i.e., unprimed, seed soaked in water for 10?hr prior to sowing, and seed soaked in 0.4% gypsum solution for 10?hr prior to sowing) were assessed on growth and yield of wheat (Triticum aestivum L.) crop in alkali soil in northwestern Pakistan. A split plot design was used, keeping priming methods in main plots and soil amendments in sub-plots. The results showed that the effects of soil amendments and seed priming on grain yield, straw yield, harvest index and number of spikes were significant but their interactive effect was non-significant. The highest crop yields and yield index were obtained with gypsum?+?FYM amendments, and seed priming with gypsum solution. The effect on seed emergence, plant height and number of grains per spike was, however, not significant. Grain yield increased by 104% in gypsum?+?FYM treatment over control and by 16.8% with seed primed in water, followed by 8.5% with priming in gypsum solution, as compared to non-priming. The weight of 1000 grains was significantly increased by 35% in gypsum?+?FYM treatment and by 15.8% in gypsum priming. The phosphorus (P) and potassium (K) content increased with soil amendments. Soil pH and gypsum requirement reduced significantly with soil amendments. The blend of gypsum and FYM has improved the properties of salt-affected soil and enhanced fertility for optimum production of wheat in addition to the beneficial effect of seed priming in gypsum solution on crop yield. Using these amendments could be ameliorative in removing the adverse effect of the salt-affected soils, rendering the soil a good medium for plant growth.     

Gaseous carbon emission in relation to soil carbon fractions and microbial diversities as affected by organic amendments in tropical rice soil

The interactive effects of moisture and organic amendments (farmyard manure (FYM), crop residue (CR) and green manure (GM) (Sesbania aculeata) on gaseous carbon (C) emission, soil labile C fractions, enzymatic activities and microbial diversity in tropical, flooded rice soil were investigated. The amendments were applied on equal C basis in two moisture regimes, that is, aerobic and submergence conditions. The CO₂ production was significantly higher by 22% in aerobic than in submergence condition; on the contrary, the CH₄ production was 27% higher under submergence condition. The labile C fractions were significantly higher in GM by 26% under aerobic and 30% under submergence conditions, respectively, than control (without any kind of fertilizer or amendments). Eubacterial diversity identified by PCR-DGGE method (polymerase chain reaction coupled with denaturant gradient gel electrophoresis) was higher under GM followed by FYM, CR, and control and it is pronounced in submerged condition. GM favored the labile C accumulation and biological activities under both submergence and aerobic conditions, which makes it most active for soil–plant interactions compared to other organic amendments. Considering environmental sustainability, the use of GM is the better adoptable option, which could enhance labile C pools, microbial diversities in soil and keep soil biologically more active.     

Influence of Long‐Term Application of Organic and Inorganic Fertilizer to Build Up Soil Fertility and Nutrient Uptake in Mint‐Mustard Cropping Sequence

Abstract

Field experiment was conducted for 7 years continuously to evaluate the influence of combined application of organic and inorganic fertilizer on soil fertility buildup and nutrient uptake in mint (Mentha arvensis) and mustard (Brassica juncea) cropping sequence. Maximum organic carbon was observed under full supply of organic manure (T₂; FYM at 20 t ha^?1) averaged across all the Stages of cropping sequence. It was increased by 38, 50, and 51% in T₂ in Stages I (after mint harvest/presowing of dhaincha), II (after incorporation of dhaincha (Sesbania aculeata)/presowing of mustard), and III (after harvest of mustard/preplanting of mint), respectively, over their respective controls. In general, magnitude of organic carbon was recorded higher in Stage II after green manuring of Sesbania compared with Stages I and III. Nitrogen availability in treated plots was increased by 26.0–89.9, 15.2–64.5, and 4.9–52.0% in Stages I (after mint harvest/presowing of Sesbania), II (after incorporation of dhaincha/presowing of mustard), and III (after harvest of mustard/preplanting of mint), respectively, over their respective control. Average across all the three Stages showed a positive balance of nitrogen (N), phosphorus (P), and potassium (K) in soil under different treatments. Mean of the three Stages indicated that maximum available N, P, and K were increased by 36.1, 129.0, and 65.20% in T₄ (N:P:K: 133:40:40 and FYM at 6.7 t ha^?1), T₄ (N:P:K::133:40:40 and FYM at 6.7 t ha^?1), and T₃ (N:P:K::100:30:30 and FYM at 10 t ha^?1), respectively, over their initial status. Supply of organic and inorganic fertilizer (T₄; N:P:K::133:40:40 and FYM at 6.7 t ha^?1) was found most suitable combination with respect to N, P availability in soil, and productivity of mint and mustard crop.     

Soil organic carbon and physical properties as affected by long-term application of FYM and inorganic fertilizers in maize–wheat system

The physical quality of the soil, which creates suitable environment for the availability and uptake of the plant nutrients, is generally ignored. Though the effect of organic manures on soil physical quality has been widely appreciated but that of inorganic fertilizers is studied to a lesser extent. The present study carried out during 2004–2005 aims to characterize the soil physical quality in relation to the long-term (32 years) application of farmyard manure (FYM) and inorganic fertilizers in maize (Zea mays L.) wheat (Triticum aestivum L.) cropping system. The treatments during both maize and wheat crops were (i) farm yard manure at 20 Mg ha⁻¹ (FYM), (ii) nitrogen at 100 kg ha⁻¹ (N₁₀₀), (iii) nitrogen and phosphorus at 100 and 50 kg ha⁻¹ (N₁₀₀P₅₀) and (iv) nitrogen, phosphorus and potassium at 100, 50 and 50 kg ha⁻¹ (N₁₀₀P₅₀K₅₀) in addition to (v) control treatment, i.e. without any fertilizer and/or FYM addition. The treatments were replicated four times in randomized block design in a sandy loam (Typic Ustipsament, non-saline, slightly alkaline). Bulk density, organic carbon content, structural stability of soil aggregates and water holding capacity of 0–60 cm soil layer were measured.The application of FYM to maize increased the organic carbon by 16% whereas N₁₀₀P₅₀K₅₀ increased it by 21%. The increased organic matter with both FYM and N₁₀₀P₅₀K₅₀ increased the total soil porosity and decreased soil bulk density from that in control plots. The mean weight diameter (MWD) was highest in FYM plots of both maize (0.160 mm) and wheat (0.172 mm) closely followed by that in N₁₀₀P₅₀K₅₀ plots. The effect of FYM in increasing the MWD decreased with soil depth. The average water holding capacity (WHC) was higher with FYM and N₁₀₀P₅₀K₅₀ application than that in control plots. The MWD, total porosity, OC content and WHC improved with the application of balanced application of fertilizers. The grain yield and uptake of N, P and K by both maize and wheat were higher with the application of FYM and inorganic fertilizers than in control plots. The uptake of N, P and K increased with the application of FYM and N₁₀₀P₅₀K₅₀.     

Long‐term effects of organic manure and manufactured fertilizer additions on soil quality and sustainable productivity of finger millet under a finger millet–groundnut cropping system in southern India

In a 20‐yr‐old long‐term experiment, the impact of continuous application of organic manures and inorganic fertilizers on soil quality and the sustainability of finger millet production was conducted on two cropping systems: finger millet and finger millet–groundnut on an Alfisol of semi‐arid southern India. The study was conducted from 1992 to 2011 at the All India Coordinated Research Project for Dryland Agriculture, UAS, Bangalore, using a randomized block design. The treatments comprised of T₁: control [no fertilizer and no farmyard manure (FYM) applied], T₂: FYM 10 t/ha, T₃: FYM 10 t/ha + 50% of recommended NPK (50:50:25 kg/ha), T₄: FYM 10 t/ha + 100% of recommended NPK and T₅: 100% recommended NPK. Comparison of long‐term yield data between treatments was used to calculate a ‘sustainability yield index’ (SYI), which was greatest for T₄ (FYM 10 t/ha + 100% of recommended NPK), in both rotational (0.68) and monocropping (0.63) situations. Soil quality indices were determined using principal component analysis linear scoring functions. The key indicators which contributed to the soil quality index (SQI) under rotation were organic C; potentially available N; extractable P, K and S; exchangeable Ca and Mg; dehydrogenase activity and microbial biomass C and N. The largest SQI (7.29) was observed in T₄ (FYM 10 t/ha + 100% NPK), and the smallest (3.70) SQI was for the control. Application of 10 t/ha FYM together with NPK (50:50:25 kg/ha) sustained a mean yield of 3884 kg/ha.     

Effect of addition of organic residues,farmyard manure and fertilizer nitrogen on soil fertility in rice‐wheat cropping system

A field experiment was conducted for 3 crop years (July‐June) at the Indian Agricultural Research Institute, New Delhi to study the effects of Sesbania and cowpea green manuring (GM) and incorporation of mungbean residues after harvesting grain, Leucaena loppings, FYM and wheat straw incorporation before planting rice and application of 0,40,80 and 120 kg N ha^?1 to rice on the soil organic carbon (SOC), alkaline permanganate oxidizable N (APO‐N), 0.5 M sodium bicarbonate extractable P (SBC‐P) and 1N ammonium acetate exchangeable K (AAE‐K) in surface 0–15 cm soil after the harvest of rice and wheat grown in sequence. Green manuring and addition of organic residues prevented the decline in SOC. On the other hand addition of N fertilizer tended to decrease SOC after rice harvest. On the contrary application of green manures, organic residues, FYM and fertilizer N increased APO‐N, which indicates the benefit of these treatments to a more labile soil organic N pool. Also application of green manures, organic residues, FYM and fertilizer N increased SBC‐P. Not much change was observed in AAE‐K by the treatments applied.     

Comparative Effects of Organic and Inorganic Fertilizers on Soil Organic Carbon and Wheat Productivity under Arid Region

ABSTRACT

Organic amendments in the soil perform better than synthetic fertilizers in regards to soil fertility and sustainable crop productivity. Experiments were conducted to compare the effects of organic and synthetic fertilizers on soil fertility and wheat (Triticum aestivum L.) productivity. Soil fertility and protein contents of wheat grains (13.2% and 13.3% during 2005–06 and 2006–07, respectively) were improved by organic amendments. However, synthetic fertilizer (at the rate of 150, 100, and 60 kg ha^?1 N, P₂O₅, and K₂O, respectively) applications resulted in the maximum grain yield (4.05 and 4.46 t ha^?1 during 2005–06 and 2006–07, respectively). The observed and simulated soil organic carbon (SOC) reasonably agreed during RothC model validation (R ² = 0.99). Economic analysis showed the maximum net profit and relative increase in income ($729 US ha^?1 and 309%, respectively) from inorganic treatment. Application of synthetic fertilizers increased grain yield and farm profit while organic manure enhanced grain quality. The RothC model had potential for determining the SOC in organic farming under arid environment.     

Long‐term effects of fertilization on some soil properties under rainfed soybean‐wheat cropping in the Indian Himalayas

This study aims to examine the effects of long‐term fertilization and cropping on some chemical and microbiological properties of the soil in a 32 y old long‐term fertility experiment at Almora (Himalayan region, India) under rainfed soybean‐wheat rotation. Continuous annual application of recommended doses of chemical fertilizer and 10 Mg ha^–1 FYM on fresh‐weight basis (NPK + FYM) to soybean (Glycine max L.) sustained not only higher productivity of soybean and residual wheat (Triticum aestivum L.) crop, but also resulted in build‐up of total soil organic C (SOC), total soil N, P, and K. Concentration of SOC increased by 40% and 70% in the NPK + FYM–treated plots as compared to NPK (43.1 Mg C ha^–1) and unfertilized control plots (35.5 Mg C ha^–1), respectively. Average annual contribution of C input from soybean was 29% and that from wheat was 24% of the harvestable aboveground biomass yield. Annual gross C input and annual rate of total SOC enrichment from initial soil in the 0–15 cm layer were 4362 and 333 kg C ha^–1, respectively, for the plots under NPK + FYM. It was observed that the soils under the unfertilized control, NK and N + FYM treatments, suffered a net annual loss of 5.1, 5.2, and 15.8 kg P ha^–1, respectively, whereas the soils under NP, NPK, and NPK + FYM had net annual gains of 25.3, 18.8, and 16.4 kg P ha^–1, respectively. There was net negative K balance in all the treatments ranging from 6.9 kg ha^–1 y^–1 in NK to 82.4 kg ha^–1 y^–1 in N + FYM–treated plots. The application of NPK + FYM also recorded the highest levels of soil microbial‐biomass C, soil microbial‐biomass N, populations of viable and culturable soil microbes.     

减施化肥和配施有机肥对酿酒葡萄梅鹿辄产量和品质的影响

[目的]针对河西灌区土壤肥力贫瘠,酿酒葡萄产量与品质低下及无机氮肥过量施用造成的环境问题,通过探究有机氮替代部分无机氮肥对酿酒葡萄生长、产量及品质的影响,以确定酿酒葡萄适宜的有机无机氮肥配施用量.[方法]于2018年在甘肃省张掖市临泽县进行田间试验,采用随机区组设计,设6个处理:单施化肥(C),单施有机肥(O),70％...     

Effects of Long-Term Fertilizer Application and Rainfall Distribution on Cotton Productivity,Profitability, and Soil Fertility in a Semi-arid Vertisol

Long-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–cost ratio 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.     

Effects of Organic Amendments on Soil Physical Attributes and Aggregate-Associated Phosphorus Under Long-Term Rice-Wheat Cropping

The quantification of phosphorus(P) in bulk soil and P distribution in different size fractions of water-stable aggregates(WSAs)are important for assessing potential P loss through runoff. We evaluated available and total P distribution within WSAs of a sitty clay to clay soil in a long-term fertility experiment of a rice-wheat cropping system in India. Surface soil samples were collected from seven plots amended with NPK fertilizers in combination with or without organic amendments, farmyard manure(FYM), green manure(GM), and paddy straw(PS). The plot with no NPK fertilizers or organic amendments was set as a control. The soil samples were separated by wet sieving into four soil aggregate size fractions: large macroaggregates( 2.0 mm), small macroaggregates(0.25–2.0 mm), fine microaggregates(0.05–0.25 mm), and a silt + clay-sized fraction( 0.05 mm). Structural indices were higher in the soil receiving organic amendments than in the soil receiving inorganic fertilizer alone. Organically amended soil had a higher proportion of stable macroaggregates than the control and the soil receiving inorganic fertilizer alone, which were rich in microaggregates. Total and available P contents within WSAs were inversely related to the aggregate size, irrespective of treatment. The distribution of available and total P in the soil aggregate size fraction was as follows: silt + clay-size fraction small macroaggregates fine microaggregates large macroaggregates. Within a size class, aggregate-associated available and total P contents in the organically amended soil were in the following order: FYM PS ≥ GM. The available P content of the microaggregates( 0.25 mm) was 8-to 10-times higher than that of the macroaggregates( 0.25 mm), and the total P content of the microaggregates was 4-to 5-times higher than that of the macroaggregates. Cultivation without organic amendments resulted in more microaggregates that could be checked by the application of organic amendments such as FYM and GM, which increased the proportion of water-stable macroaggregates by consolidating microaggregates into macroaggregates.