Identification of Minimum Data Set Under Balanced Fertilization for Sustainable Rice Production and Maintaining Soil Quality in Alluvial Soils of Eastern India

The scarcity of non-renewable fertilizers resources and the consequences of climate change can dramatically influence the food security of future generation. Introduction of high yielding varieties, intensive cropping sequence and increasing demand of food grains day-by-day, application of recommended dose of fertilizers could not fulfill our targets due to outdated fertilizers recommendations are yet in practice. It not only alters soil quality, nutrient balance, microbial and enzymatic ecology but also affected productivity and sustainability of rice in Gangetic alluvial soils of India. The effect of fertilizers application based on “fertilizing the soil versus fertilizing the crop” which insure real balance between the applied and available soil nutrient is urgently needed. Hence, the present study was conducted during three consecutive crop seasons (2010, 2011, and 2012) to assess the effect of imbalance and balance fertilization based on initial soil test values and targeted yields, and to determine the effect of farmyard manure (FYM) when superimposed with balanced fertilizers on identification of minimum data set for the development soil quality, nutrient acquisition, and grain yield of rice. The six fertilizer treatments were laid out in a randomized block design with three replications. The treatments were: T₁-control (no fertilization), T₂-farmyard manure @ 5 t ha^?1, T₃-farmers practice (60:30:30 kg N:P₂O₅:K₂O ha^?1), T₄-precise application of mineral fertilizers based on initial soil test values (77:24:46 kg N:P₂O₅:K₂O ha^?1) for targeted grain yield of 4.0 t ha^?1, T₅-precise application of mineral fertilizers based on initial soil test values (74:23:43 kg N:P₂O₅:K₂O ha^?1) plus FYM (5 t ha^?1) for targeted grain yield of 4.0 t ha^?1 and T₆-precise application of mineral fertilizers based on initial soil test values (135:34:65 kg N:P₂O₅:K₂O ha^?1) for targeted rice grain yield of 5.0 t ha^?1. Result revealed that the targeted rice grain yield of 4.0 and 5.0 t ha^?1 was achieved in T₄ and T₆ treatments with 1.59% (4.06 t ha^?1) and –3.40% (4.83 t ha^?1) deviations, respectively. T₄, T_5, and T₆ significantly increased crop growth, nutrient uptake, available P (P_a) and K (K_a) and augmented rice grain yield by 10.6, 20.2 and 31.6%, respectively, over T₃. Microbial biomass carbon, soil respiration and enzymatic activity were enhanced significantly in T₅ as compared to T₆. Highest soil quality index was found in T₅ (0.95) followed by T₆ (0.90) and, lowest was in T₁ (0.63). The contribution of minimum data set (MDS) toward the SQI was in the descending order of ALP (30.6%) > SOC (21.5%) > K_a (11.3%) > PSM (9.68%) > N_a (8.51%). Overall, rice yield and soil quality was improved by using balance fertilization based on fertilizing the crop Vs fertilizing the soil in alluvial soils of India.     

Productivity,Quality and Soil Health as Influenced by Organic,Inorganic and Biofertilizer on Field Pea in Eastern Himalaya

A field experiment was conducted during two consecutive years of 2010–2011 and 2011–2012 to study the effect of biofertilizers in conjunction with organic and inorganic sources of nutrient management on productivity, quality and soil health on field pea at ICAR RC for NEH Region, Nagaland Centre Jharnapani, Nagaland, India. The experiment was laid out in split plot design with five nutrient sources in main plots and four treatment of biofertilizers with zinc in sub plots. Results indicated that the application of 100% recommended dose of fertilizer (RDF) through inorganic + 50% recommended dose of nitrogen (RDN) through vermicompost significantly improved root nitrogen (N) content, cation exchange capacity (CEC) of roots, NA activates, seed yield (1153 and 1262 kg ha^?1), straw yield (2182 and 2332 kg ha^?1) in the year of 2010–2011 and 2011–2012, respectively. Nutrients (N, P, K, S and Zn) uptake by seed and straw, protein content, protein harvest, soil organic carbon (SOC), available N, P, K, S, Zn and economics significantly higher with 100% RDF through inorganic + 50% RDN through vermicompost during both the years. Seed inoculation with biofertilizers along with 5 kg Zn ha^?1 markedly enhanced the root N content, CEC of roots, nitrogenase activities (NA), seed yield (1080 and 1193 kg ha^?1), straw yield (1978 and 2128 kg ha^?1), nutrients [N, phosphorus (P), potassium (K), sulfur (S) and zinc (Zn)] uptake, soil organic carbon (SOC) (%), and available N, P, K, S, and Zn of pea in both the years, respectively. These sources also give more income and benefit cost ratio per rupees invested.     

Effects of Organic and Inorganic Fertilizers on Soil and Plant Nutrients and Yields of Pearl Millet and Wheat under Semi-arid Inceptisols in India

A study was conducted to assess fertilizer effect on pearl millet–wheat yield and plant-soil nutrients with the following treatments: T₁, control; T₂, 100% nitrogen (N); T₃, 100% nitrogen and phosphorus (NP); T₄, 100% nitrogen, phosphorus and potassium (NPK); T₅, 100% NPK + zinc sulfate (ZnSO₄) at 25 kg ha^?1; T₆, 100% NPK + farmyard manure (FYM) at 10 t ha^?1; T₇, 100% NPK+ verimcompost (VC) at 2.5 tha^?1; T₈, 100% NPK + sulfur (S) at 25 kg ha^?1; T₉, FYM at 10 t ha^?1; T₁₀, VC at 2.5 t ha^?1; T₁₁, 100% NPK + FYM at 10 t ha^?1 + 25 kg S ha^?1 + ZnSO₄ at 25 kg ha^?1; and T₁₂, 150% NPK treatments. Treatments differed significantly in influencing soil-plant nutrients and grain and straw yields of both crops. Grain yield had significant correlation with soil-plant N, P, K, S, and zinc (Zn) nutrients. The study indicated superiority of T₁₁ for attaining maximum pearl millet grain yield (2885 kg ha^?1) and straw yield (7185 kg ha^?1); amounts of N (48.9 kg ha^?1), P (8.8 kg ha^?1), K (26.3 kg ha^?1), S (20.6 kg ha^?1), and Zn (0.09 kg ha^?1) taken up; and amounts of soil N (187.7 kg ha^?1), P (13.7 kg ha^?1), K (242.5 kg ha^?1), S (10.1 kg ha^?1), and Zn (0.70 kg ha^?1). It was superior for wheat with grain yield (5215 kg ha^?1) and straw yield (7220 kg ha^?1); amounts of N (120.7 kg ha^?1), P (13.8 kg ha^?1), K (30 kg ha^?1), S (14.6 kg ha^?1), and Zn (0.18 kg ha^?1) taken up; and maintaining soil N (185.7 kg ha^?1), P (14.5 kg ha^?1), K (250.5 kg ha^?1), S (10.6 kg ha^?1), and Zn (0.73 kg ha^?1). Based on the study, 100% NPK + FYM at 10 tha^?1 + Zn at 25 kg ha^?1 + S at 25 kg ha^?1 could be recommended for attaining maximum returns of pearl millet–wheat under semi-arid Inceptisols.     

Carrier-based and liquid bioinoculants of Azotobacter and PSB saved chemical fertilizers in wheat (Triticum aestivum L.) and enhanced soil biological properties in Mollisols

Abstract

The increasing cost and imbalanced use of chemical fertilizers in wheat (Triticum aestivum L.) stressed the need to explore the potential of bioinoculants of Azotobacter and PSB for saving fertilizer N and P. Field experiments conducted for two years in a Mollisol at Pantnagar revealed maximum plant height, grain and straw yields and nutrient uptake by wheat with application of 100% NP. However, soil application of carrier-based biofertilizer at 10?kg?ha^?1 and liquid-based biofertilizers at 625 and 1250?mL?ha^?1 rates in combination of 75% NP were at par with 100% NP by recording significantly more mean plant height at different intervals, grain yield, by 10.9, 10.5 and 10.8%, and straw yield, by 8.6, 8.2 and 9.1%, over 75% NP, respectively. These treatments also accumulated significantly more N, P and K in plant at different age and; grain and straw. An application of liquid biofertilizer at 1250?mL?ha^?1 with 75% NP gave maximum population of Azotobacter and PSB, microbial biomass C and activities of acid and alkaline phosphatase in soil at different crop age. The carrier and liquid formulations of the biofertilizers were comparable in their performance. Irrespective of formulation and doses, application of biofertilizers in soil was found better than seed treatment for different recorded parameters. An application of 625?mL?ha^?1 liquid biofertilizers in soil with 75% NP was found optimum for the growth, yield and nutrients uptake and soil biological properties.     

Plant and Soil Responses to the Combined Application of Organic Amendments and Inorganic Fertilizers in Degraded Sodic Soils of Indo-Gangetic Plains

ABSTRACT

Soil degradation due to salinization and sodication is the paramount threat in Indo-Gangetic plains. The studies on reclamation and management of such soils can provide a pragmatic solution for improving fertility and productivity of these soils. Lack of organic matter and poor availability of nutrients are the major factors for low productivity of sodic soils. Rice-wheat is a major cropping system in Indo-Gangetic alluvial plain region even in reclaimed sodic soils and farmers used inorganic fertilizers only to get higher yields. In this study, we used different organic sources of amendments in conjunction with different nitrogen (N) doses supplied through inorganic fertilizers to investigate the combined effect of organic and inorganic amendments on soil fertility and the productivity of rice- wheat system in sodic soils. Salt tolerant varieties of rice and wheat were grown in sodic soil (pH: 9.30, EC: 1.12 dSm^?1 and exchangeable sodium percentage, ESP: 52) during 2014–15 to 2016–17 in a field experiment with 13 treatment combinations of organic and inorganic amendments (T₁- (control) 100% of recommended dose of N (RDN), T₂-municipal solid waste compost (MSWC) @10 t ha^?1 + 50%RDN, T₃- MSWC @10 t ha^?1 + 75% RDN,T₄- MSWC @10 t ha^?1 + 100%RDN, T₅-Vermicompost (VC) @10 t ha^?1 + 50% RDN, T₆- VC @10 t ha^?1 + 75% RDN, T₇-VC@10 t ha^?1 + 100% RDN, T₈- Farm yard manure (FYM) @ 10 t ha^?1 + 50% RDN,T₉- FYM@10 t ha^?1 + 75%RDN, T₁₀- FYM@10 t ha^?1 + 100% RDN, T₁₁-Pressmud (PM) @10 t ha^?1 + 50% RDN, T₁₂-PM@10 t ha^?1 + 75%RDN, and T₁₃- PM @ 10 t ha^?1 + 100% RDN). Use of organic amendments supplemented with reduced dose of N through inorganic fertilizer has significantly improved soil bio-physical and chemical properties. Application of VC@10 t ha^?1 + 100% RDN (T₇) decreased soil bulk density, pH, EC, ESP and Na content to 2.0, 4.2, 26.5, 42.8, and 56.6% respectively and increased soil organic carbon by 34.6% over control (T₁). Soil fertility in terms of available N, P, K, Ca, and Mg increased by 20.5, 33.0, 36.4, and 44%, respectively, over control (T₁). Soil microbial biomass carbon, nitrogen, and phosphorus also improved significantly due to combined use of organic amendments and inorganic fertilizers over the only use of inorganic fertilizers. Decreasing in soil sodicity and increasing soil fertility showed significant increase (P < 0.05) in crop growth, growth indices, and grain yields of rice and wheat. The study revealed that combined use of VC or MSW compost @10 t ha^?1 in conjunction with 75% RDN through inorganic fertilizers in sodic soils proved sustainable technology for restoration of degraded sodic soils and improving crop productivity.     

Effects of biochar compared to organic and inorganic fertilizers on soil quality and plant growth in a greenhouse experiment

Our contemporary society is struggling with soil degradation due to overuse and climate change. Pre‐Columbian people left behind sustainably fertile soils rich in organic matter and nutrients well known as terra preta (de Indio) by adding charred residues (biochar) together with organic and inorganic wastes such as excrements and household garbage being a model for sustainable agriculture today. This is the reason why new studies on biochar effects on ecosystem services rapidly emerge. Beneficial effects of biochar amendment on plant growth, soil nutrient content, and C storage were repeatedly observed although a number of negative effects were reported, too. In addition, there is no consensus on benefits of biochar when combined with fertilizers. Therefore, the objective of this study was to test whether biochar effects on soil quality and plant growth could be improved by addition of mineral and organic fertilizers. For this purpose, two growth periods of oat (Avena sativa L.) were studied under tropical conditions (26°C and 2600 mm annual rainfall) on an infertile sandy soil in the greenhouse in fivefold replication. Treatments comprised control (only water), mineral fertilizer (111.5 kg N ha^–1, 111.5 kg P ha^–1, and 82.9 kg K ha^–1), compost (5% by weight), biochar (5% by weight), and combinations of biochar (5% by weight) plus mineral fertilizer (111.5 kg N ha^–1, 111.5 kg P ha^–1, and 82.9 kg K ha^–1), and biochar (2.5% by weight) plus compost (2.5% by weight). Pure compost application showed highest yield during the two growth periods, followed by the biochar + compost mixture. biochar addition to mineral fertilizer significantly increased plant growth compared to mineral fertilizer alone. During the second growth period, plant yields were significantly smaller compared to the first growth period. biochar and compost additions significantly increased total organic C content during the two growth periods. Cation‐exchange capacity (CEC) could not be increased upon biochar addition while base saturation (BS) was significantly increased due to ash addition with biochar. On the other hand, compost addition significantly increased CEC. Biochar addition significantly increased soil pH but pH value was generally lower during the second growth period probably due to leaching of base cations. Biochar addition did not reduce ammonium, nitrate, and phosphate leaching during the experiment but it reduced nitrification. The overall plant growth and soil fertility decreased in the order compost > biochar + compost > mineral fertilizer + biochar > mineral fertilizer > control. Further experiments should optimize biochar–organic fertilizer systems.     

Growth and yield of lowland rice as affected by integrated nutrient management and cultivation method under alternate wetting and drying water regime

The effects of integrated nutrient management, cultivation method, and variety on root and shoot growth, grain yield and its components of lowland rice under alternate wetting and drying (AWD) irrigation were evaluated. Treatments included were three varieties (Pathumthani 1, RD57, and RD41), three cultivation methods [dry direct seeding, wet direct seeding, and transplanting], and three nutrient combinations [100% NPK (160?kg ha^?1), 50% NPK (80?kg ha^?1) + 50% FYM (5 t ha^?1), and 100% FYM (10 t ha^?1)] under AWD. Root dry matter of RD41 and RD57 was reduced by 12–25% at the 100% NPK and 100% FYM compared with the 50% NPK + 50% FYM. Panicle number, panicle length, and 1000-grain weight were higher at the 50% NPK + 50% FYM. Application of the 50% NPK + 50% FYM could be a feasible option under AWD irrigation; however, benefits may vary with varieties and cultivation methods.     

Cumulative Effect of Organic and Inorganic Sources of Nutrients on Yield,Nutrients Uptake and Economics by Rice–Wheat Cropping System in Indo-Gangetic Plains of India

ABSTRACT

Field experiments were conducted for 2 years in sandy loam soil, to study the direct effect of organic manures i.e. sewage sludge (SS), vermicompost (VC) and sesbania (SB) and chemical fertilizers on rice (Oryza sativa) and their residual effect on wheat (Triticum aestivum) grown in sequence in winter (Rabi) and summer (Kharif) season during 2015–2016 to 2016–2017 at Varanasi, Uttar Pradesh. Residual effect of organic sources of nutrients as SS, VC and SB were monitored up to fourth crop (II wheat) in sequence applied in conjunction with 75% recommended dose of fertilize (RDF). Among the nutrient sources, the maximum grain yield in I rice (4.89 t ha^?1), II rice (4.95 t ha^?1), was recorded in treatment T₃ (100% RDF with S, Zn, B) whereas in I wheat (4.68 t ha^?1) and II wheat (4.59 t ha^?1), it was recorded in T₄ (customized fertilizer). The maximum straw yield during all four crops was recorded in T₃ (100% RDF with S, Zn, B) in rice and T₄ (customized fertilizer) in wheat crop, which showed 25, 32, 23 and 28% increase over 100% RDF (T₂). Application of 100% RDF along with S, Zn, B and customized fertilizer increased the total uptake of N, P, K, S and B and also in net returns and B:C ratio followed by organic treatments.     

Effects of Conjunctive Nutrient Management on Soil Fertility and Overall Soil Quality Index in Submountainous Inceptisol Soils under Rainfed Maize (Zea mays L.)–Wheat (Triticum aestivum) System

The present long-term study was initiated to quantify the long-term effects of conjunctive nutrient management on soil quality, identify key indicators, and assess soil quality indices under a rainfed maize–wheat system in marginal Inceptisol soils in India. Results of the study revealed that soil organic carbon was significantly influenced by the conjunctive nutrient-management treatments. Among the nine treatments, the application of 100% recommended dose of nitrogen (RDN) (80 kg N ha^?1), 15 kg N (compost) + 20 kg N ha^?1 (inorganic), 25 kg N (compost), and 15 kg N (compost) + 10 kg N ha^?1 (green leaf) resulted in greater organic carbon contents of 5.57, 5.32, 5.27, and 5.26 g kg^?1, which were greater by 29.5%, 24%, 23%, and 22%, respectively, over the control. The greatest soil quality index (1.61) was observed with application of 25 kg nitrogen (N; compost) as well as with application of 15 kg N (compost) + 10 kg N ha^?1 (green leaf). The order of percentage contribution of key indicators toward soil quality indices was available potassium (K) (34%) > available phosphorus (P) (32%) > available N (13%) > microbial biomass carbon (12%) > exchangeable calcium (Ca) (9%). The linear regression equation revealed the principal role of soil quality indicators in maize crop yield. The methodology and the results of the study could be of great relevance in improving and assessing soil quality not only for the study locations but also for other climatically and edaphically identical regions across the world.     

Effect of Integrated Nutrition in Aromatic Rice on Carbon and Nutrient Status in an Inceptisol

Inorganic fertilizer-based nutrient management is the maintenance of soil fertility for sustaining increased crop productivity, but often at the cost of degrading soil health. This study was conducted to determine whether incorporation of organics in the conventional inorganic-based nutrient management practice on aromatic rice could sustain both fertility and soil organic carbon status on a silt loam Aeric Haplaquept. Addition of organic manure along with inorganic fertilizer could almost maintain organic carbon status of soil, while the treatment only with inorganic fertilizer registered a substantial decrease (6.58%) from its initial value. Among the treatment combinations, the treatment receiving 1 t ha^?1 mustard cake and inorganic fertilizer @ N₄₀P₂₀K₂₀ was the best, which registered the highest grain (3.01 t ha^?1) and straw (5.32 t ha^?1) yield of rice, highest nutrient uptake, and least decline in available N, P, and K status of soil. However, even the best treatment combination also was proved to be suboptimal in sustaining soil fertility.     

Combined use of millet glume-derived compost and mineral fertilizer enhances soil microbial biomass and pearl millet yields in a low-input millet cropping system in Niger

A two-year field experiment was conducted in Niger to explore the effects of integrated use of millet glume-derived compost (MGD-Compost) and NP fertilizer on soil microbial biomass carbon (C_mic), nitrogen (N_mic) and millet yields. Three compost rates (3000 kg ha^?1, 1500 kg ha^?1 and 0 kg ha^?1) and three NP fertilizer rates (100%, 50% and 0% of recommended NP fertilizer) were arranged in a factorial experiment organized in a randomized complete block design with three replications. Combined application of compost and NP fertilizer induced a synergistic effect on C_mic and N_mic. Compost application increased millet grain yield from 59% to 91% compared to control. Combined application of compost and NP fertilizer increased millet grain yields from 57% to 70% in 2013 and from 36% to 82% in 2014 compared to sole application of mineral fertilizer. Agronomic efficiency (AE) of nitrogen values increased by 3.7 and 2.3 times than those of sole NP fertilizer application in 2013 and 2014, respectively. Phosphorus AE was 1.6 times higher than that of the sole application of NP fertilizer. These findings indicate that integrated application of MGD-Compost and NP fertilizer enhances soil microbial biomass content and increases millet grain yield in a low-input cropping system.     

Effect of long‐term fertilization and manuring on potassium release properties in a Typic Ustochrept

A long‐term fertilizer experiment, over 27 years, studied the effect of mineral fertilizers and organic manures on potassium (K) balances and K release properties in maize‐wheat‐cowpea (fodder) cropping system on a Typic Ustochrept. The treatments consisted of control, 100% nitrogen (100% N), 100% nitrogen and phosphorus (100% NP), 50% nitrogen, phosphorus, and potassium (50% NPK), 100% nitrogen, phosphorus, and potassium (100% NPK), 150% nitrogen, phosphorus, and potassium (150% NPK), and 100% NPK+farmyard manure (100% NPK+FYM). Nutrients N, P, and K in 100% NPK treatment were applied at N: 120 kg ha^—1, P: 26 kg ha^—1, and K: 33 kg ha^—1 each to maize and wheat crops and N: 20 kg ha^—1, P: 17 kg ha^—1, and K: 17 kg ha^—1 to cowpea (fodder). In all the fertilizer and manure treatments removal of K in the crop exceeded K additions and the total soil K balance was negative. The neutral 1 N ammonium acetate‐extractable K in the surface soil (0—15 cm) ranged from 0.19 to 0.39 cmol kg^—1 in various treatments after 27 crop cycles. The highest and lowest values were obtained in 100% NPK+FYM and 100% NP treatments, respectively. Non‐exchangeable K was also depleted more in the treatments without K fertilization (control, 100% N, and 100% NP). Parabolic diffusion equation could describe the reaction rates in CaCl₂ solutions. Release rate constants (b) of non‐exchangeable K for different depth of soil profile showed the variations among the treatments indicating that long‐term cropping with different rates of fertilizers and manures influenced the rate of K release from non‐exchangeable fraction of soil. The b values were lowest in 100% NP and highest in 100% NPK+FYM treatment in the surface soil. In the sub‐surface soil layers (15—30 and 30—45 cm) also the higher release rates were obtained in the treatments supplied with K than without K fertilization indicating that the sub‐soils were also stressed for K in these treatments.     

Soil management for raising crop water productivity in rainfed production systems in Lao PDR

This study investigated the impacts of organic- and clay-based soil amendments, and their combinations on crop water productivity (CWP) using maize as a test crop. On-station field trials were established over two consecutive years at the Naphok and Veunkham sites in Laos. At each site, 10 treatments were applied in a randomized complete block design with three replications. The treatments were control, rice husk biochar (10 t ha^?1), bentonite clay (10 t ha^?1), compost (4 t ha^?1), clay-manure compost (10 t ha^?1), rice husk biochar compost (10 t ha^?1), bentonite clay + biochar, bentonite-clay + compost, biochar + compost, and bentonite clay + biochar + compost. All treatments were applied in 2011. Significant (p < 0.05) treatment effects in CWP and growing period evapotranspiration were determined. At Naphok, differences between the amended and control plots in CWP varied between 0.1 and 0.6 kg m^?3 in 2011 and from 0.1 to 0.4 kg m^?3 in 2012, whereas differences at Veunkham varied between 0.3 and 1.0 kg m^?3 in 2011 and from 0.05 to 0.29 kg m^?3 in 2012. At both sites, CWP in 2012 was significantly lower than 2011. Our results illustrate that organic- and clay-based soil amendments improve CWP, indicating that soil-based interventions could be suitable options for improving agricultural productivity.     

Management practices of macronutrients for potato for smallholder farming system at alluvial soil (Entisols) of India

In the present study, seven fertilizer treatments [T₁, 50% NPK; T₂, 100% NPK (Recommended dose of fertilizer, 200–65.4–124.5 kg N-P-K ha^?1); T₃, 150% NPK; T₄, 100% PK; T₅, 100% NK; T₆, 100% NP and T₇, control (zero NPK)] with four replications were assessed in the new alluvial soil zone (Entisols) of West Bengal, India. The objectives of the study were to generate information on potato productivity, profitability, indigenous nutrient supply and net gain/loss of NPK in post-harvest soil. Plants grown under higher NPK supply resulted in higher tuber yield and there were significant (p ≤ 0.05) reductions in total yield with nutrient omissions. Nutrient?limited yields were 19.78, 2.83 and 1.77 t ha^?1 for N, P and K, considering total tuber yield (28.24 t ha^?1) obtained under 100% NPK as targeted yield. Indigenous nutrient supply of N, P and K were estimated at 24.1, 22.34 and 110.22 kg ha^?1, respectively that indicates higher K?supplying capacity of experimental soil as compared to N and P. Net income (US$1349 ha^?1 year^?1) and B:C ratio (1.91) was highest with 100% NPK, and further addition of NPK (150%) resulted in decrease on net return (US$1193 ha^?1 year^?1) and B:C ratio (1.73).     

Improving soil organic carbon pools through inclusion of summer mungbean in cereal-cereal cropping systems in Indo-Gangetic plain

Long-term effect of mungbean inclusion in lowland rice-wheat and upland maize-wheat systems on soil carbon (C) pools, particulate organic C (POC), and C-stabilization was envisaged in organic, inorganic and without nutrient management practices. In both lowland and upland systems, mungbean inclusion increased very-labile C (Cfrac₁) and labile C (Cfrac₂) in surface soil (0–0.2 m). Mungbean inclusion in cereal-cereal cropping systems improved POC, being higher in lowland (107.4%). Lowland rice-based system had higher passive C-pool (11.1 Mg C ha^?1) over upland maize-based system (6.6 Mg C ha^?1) indicating that rice ecology facilitates the stabilization of passive C-pool, which has longer persistence in soil. Organic nutrient management (farmyard manure + full crop residue + biofertilizers) increased Cfrac₁ and carbon management index (CMI) over inorganic treatment. In surface soil, higher CMI values were evident in mungbean included cropping systems in both lowland and upland conditions. Mungbean inclusion increased grain yield of cereal crops, and yield improvement followed the order of maize (23.7–31.3%) > rice (16.9–27.0%) > wheat (lowland 7.0–10.7%; upland 5.4–16.6%). Thus, the inclusion of summer mungbean in cereal-cereal cropping systems could be a long-term strategy to enrich soil organic C and to ensure sustainability of cereal-cereal cropping systems.     

Field efficiency of biofertilizers on the growth of okra (Abelmoschus esculentus [(L.) Moench])

An experiment was carried out at the Farm of the Department of Crop Botany, Bangladesh Agricultural University, Mymensingh from March to July, 2001 to investigate the effect of biofertilizers on morpho‐physiological characters of okra. The experiment was laid out in a randomized complete block design with four replications. There were nine treatments such as T₀ (control), T₁ (Azotobacter biofertilizer), T₂ (Azospirillum. biofertilizer), T₃ (Azotobacter + Azospirillum. biofertilizers), T₄ (Azotobacter + Cowdung 5 t ha^–1), T₅ (Azospirillum + 5 t ha^–1 cowdung), T₆ (Azotobacter + Azospirillum + 5 t ha^–1 cowdung), T₇ (5 t ha^–1 cowdung), and T₈ (60 % N). The experimental results revealed significant variations among the treatments in respect of morphological characters, e.g. plant height, number of leaves per plant, stem base diameter, tap root length, and physiological characters like root dry weight, leaf area index, and crop growth rate. Number of leaves per plant, stem base diameter, root length, root dry weight, leaf area index, and crop growth rate were larger in T₄, T₅, T₆, and T₈ than the others. In all the parameters, T₈ gave the similar result with biofertilizers in combination with cowdung treatments, and T₇ was identical with T₀ (control). These experimental results revealed that morpho‐physiological characters of okra could be modified by the application of biofertilizer + cowdung. However, biofertilizers + cowdung treatments were comparable to T₈ (60 % N) in this study. This suggests that T₄ or T₆ or T₅ were more benificial in environmentally friendly okra cultivation and may be used as an alternative of inorganic N by saving cost of production and sustaining productivity.     

Effect of magnesium on crop yields within maize–green manure–T. aman rice cropping pattern on acid soil

An experiment was conducted to study the response of maize to magnesium (Mg) and to find out the residual effect of Mg and green manure (GM) on transplanted aman (T. aman) rice in the maize–GM–T. aman cropping pattern. There were six treatments: T₁ (recommended dose of fertilizer (RDF) + 0 kg Mg + 2 t CaCO₃ ha^?1), T₂ (RDF + 10 kg Mg + 2 t CaCO₃ ha^?1), T₃ (RDF + 20 kg Mg +2 t CaCO₃ ha^?1), T₄ (RDF + 30 kg Mg + 2 t CaCO₃ ha^?1), T₅ (RDF) and T₆ (2 t CaCO₃ ha^?1). The response of maize to Mg was quadratic and the optimum dose of Mg was found to be 19 kg ha^?1, which resulted in maximum yield of 10,507 kg ha^?1. The residual effect of Mg along with GM and reduced dose of chemical fertilizer resulted in significant increase of grain yield of rice. Thus, N₂₅₀P₆₀K₁₀₀Mg₁₉S₄₀Zn₅B₂ kg ha^?1 for maize, only 20 kg N ha^?1 for GM (Sesbania) and N₆₀P₉K₃₃S₁₀Zn₁B₁ kg ha^?1 for T. aman appeared as the best combination for maximizing the productivity and may be recommended for this pattern at non-calcareous light-textured soils of Bangladesh. Application of lime increased soil pH, and this together with fertilizer and GM tended to improve soil fertility and thus may be recommended for soil amelioration.     

Effect of enriched municipal solid waste compost application on soil available macronutrients in the rice field

Abstract

A study was conducted in the Department of Environmental Sciences, Tamil Nadu Agricultural University, Coimbatore, India, to transform the normal compost into bioactive compost, which has multiple benefits to the crop system. The key players in this transformation process were Azotobacter sp., Pseudomonas sp., Phosphobacteria sp. and the waste materials like poultry litter and spent wash. This enrichment process increases both the quality and nutrient content of the municipal solid waste compost significantly. A study was carried out to evaluate the effect of application of different levels of enriched municipal solid waste compost on the availability of the macronutrient content to the rice field soil. The effect of enriched compost on soil available nutrients was significant. The soil ammonium nitrogen and soil nitrate nitrogen content was found to be high in the plots where the enriched compost was applied along with inorganic fertilizer with the values of 38.87 mg kg^?1 and 32.87 mg kg^?1, respectively. In addition, the availability decreased towards crop growth. The soil available P and K were also increased with enriched compost application to about 22.46 kg ha^?1 and 647 kg ha^?1 compared with control values of 19.44 kg ha^?1 and 518 kg ha^?1, respectively. Both phosphorus and potassium content decreased towards advancement of crop growth.     

Dynamics of zinc under long-term application of chemical fertilizers and amendments by maize–wheat cropping sequence in Typic Hapludalfs

This present investigation took place on a continuing long-term fertilizer experiment, initiated in 1972 at the experimental farm of the College of Agriculture CSK HPKV, Palampur, aimed at studying nutrient dynamics of micronutrients, especially Zn, after continuous use of chemical fertilizers and amendments over the previous 36 years in an acid Alfisol under a maize–wheat system. Treatments investigated were as follows: T₁: Control; 100% N; 100% NP; 100% NPK (optimal application - 120:26:33(maize)/25(wheat)); 100% NPK + FYM (10 t ha⁻¹ to the maize crop); T₆: 100% NPK + lime (900 kg ha⁻¹); T₇: 100% NPK + Zn (25 kg ha⁻¹ as ZnSO₄); T₈: 100% NPK + Hand weeding; T₉: 100% NPK (-S); T₁₀: 150% NPK (super-optimal application); and T₁₁: 50% NPK (sub-optimal application). Different forms of zinc in soil were determined through a sequential extraction method. Results revealed that previous applications of high-analysis fertilizers and amendments caused a marked depletion in the pools of Zn as compared to buffer plots. All pools of Zn as well as crop productivity and Zn uptake were noticeably greater in farmyard manure (FYM)-amended plots compared with plots not receiving fertilizer. The residual fraction was the dominant form but organically bound and exchangeable forms were found to play major role in nutrient supply, crop productivity and nutrient uptake. Correlation and regression analysis studies showed that organic forms constituted the most important pool contributing towards variation in yield and uptake by maize and wheat crops. Exchangeable and organically bound forms contributed significantly towards the availability of DTPA-extractable Zn in soil.     

Effects of Organic Amendments on Productivity and Profitability of Bell Pepper–French Bean–Garden Pea System and on Soil Properties during Transition to Organic Production

A transition period of at least 2 years is required for annual crops before the produce may be certified as organically grown. There is a need to better understand the various management options for a smooth transition from conventional to organic production. The purpose of this study was to evaluate the effects of different organic amendments and biofertilizers (BFs) on productivity and profitability of a bell pepper–french bean–garden pea system as well as soil fertility and enzymatic activities during conversion to organic production. For this, the following six treatments were established in fixed plots: composted farmyard manure (FYMC, T₁); vermicompost (VC, T₂); poultry manure (PM, T₃) along with biofertilizers (BF) [Rhizobium/Azotobacter + phosphorus solubilizing bacteria (Pseudomonas striata)]; mix of three amendments (FYMC + PM + VC + BF, T₄); integrated nutrient management (FYMC + NPK, T₅); and unamended control (T₆). The yields of bell pepper and french bean under organic nutrient management were markedly lower (25.2–45.9% and 29.5–46.2%, respectively) than with the integrated nutrient management (INM). Among the organic treatments, T₄ and T₁ produced greater yields of both bell pepper (27.96 Mg ha^?1) and french bean (3.87 Mg ha^?1) compared with other treatments. In garden pea, however, T₄ gave the greatest pod yield (7.27 Mg ha^?1) and was significantly superior to other treatments except T₅ and T₁. The latter treatment resulted in the lowest soil bulk density (1.19 Mg m^?3) compared with other treatments. Similarly, soil organic C was significantly greater in all the treatments (1.21–1.30%) except T₂ compared to T₆ (1.06%). Plots under INM, however, had greater levels of available nitrogen–phosphorus–potassium (NPK) than those under organic amendments. T₁ plots showed greater dehydrogenase and acid phosphatase activities compared with other treatments. However, T₄ and T₅ plots had greater activities of β-glucosidase and urease activities, respectively. The cost of cultivation was greater under organic nutrient management (except T₂) compared with INM. The latter treatment gave greater gross margin and benefit/cost (B/C) ratio for all vegetables, except that T₂ gave greater B/C ratio in garden pea compared with other treatments. We conclude that T₁ and T₄ were more suitable for enhancing the productivity of bell pepper–french bean–garden pea system, through improved soil properties, during transition to organic production.