Effect of biochar amendment on soil physical,chemical and biological properties and groundnut yield in rainfed Alfisol of semi-arid tropics

The aim of this study was to evaluate the effect of biochar and organic soil amendments on soil physicochemical and microbial load, carbon sequestration potential, nutrient uptake and yield of groundnut in acidic red soil under rainfed condition. Biochar was prepared from red gram, cotton, maize stalk and mesquite wood using pilot scale slow pyrolysis biochar unit. The above sources of biochar at the rate of 2.5 and 5 t ha^?1 and enriched farmyard manure 0.75 t ha^?1, composted coir pith 10 t ha^?1 and arbuscular mycorrhizae 100 kg ha^?1 were applied as basal with required nitrogen, phosphorous and potassium fertilizer. Biochar amendment at the rate of 5 t ha^?1 reduced the bulk density from 1.41 to 1.36 g cm^?3 and increased the soil moisture 2.5%. With respect to soil chemical changes, it raised soil pH from 5.7 to 6.3; increased the cation exchange capacity 1.4 cmol⁺ kg^?1 and enhanced the carbon buildup 4.4 t ha^?1. The significant differences in bacteria, fungi and actinomycetes population were observed between biochar and control. The nitrogen, phosphorous and potassium were better utilized under biochar and composted coir pith, which was 21, 5 and 20 kg ha^?1 higher than control. The experimental results suggested that application of biochar to acidic red soil favoured good soil physical, chemical and biological environment, and these positive changes influenced growth and yield attributes and enhanced pod yield 29% over control.     

Differential impacts of climate variability on yields of rainfed barley and legumes in semi-arid Mediterranean conditions

Climate change has emerged as a major concern for crop production. This study used a field experiment to examine the differential yield responses of barley, lentil, common vetch, and bitter vetch to weather in the Mediterranean region. Crops were grown in a 10-year rotation trial in Lebanon. Precipitation and temperature were used as explanatory variables in simple linear correlation and standardized multiple-regression analyses. Grain yields were not correlated with annual precipitation. Barley grain yield was correlated positively with precipitation from March to May (r = 0.70) and the rainfall distribution index (r = 0.71), but negatively with mean May temperature (r = –0.62) and absolute minimum temperature in January (r = –0.91). Unlike barley, legume grain yield was not correlated with any rainfall parameters. Common vetch grain yield was negatively correlated with mean May temperature (r = –0.68). Grain yield of the two vetches were also correlated negatively with the absolute minimum temperature in January, but grain yield of lentil was not correlated with any weather variable. Standardized multiple-regression analyses showed that mean May temperature had the strongest influence on grain yield of barley, lentil, and common vetch, indicating that, under climate change, higher temperature may have a more deleterious effect on grain yield than lower rainfall. The negative correlation between common vetch and barley grain yields and temperature in May suggests that early sowing to induce earlier flowering and maturity to escape the hot summer may be an option to increase common vetch and barley grain yields.     

Soil test-based nutrient balancing improved crop productivity and rural livelihoods: case study from rainfed semi-arid tropics in Andhra Pradesh,India

Widespread multinutrient deficiencies in the semi-arid tropics (SAT) are among major factors for large gaps between farmers’ current crop yields and potential yields. In this study, we adopted a stratified soil sampling method to assess soil fertility-related constraints in farmers’ fields in eight districts of Andhra Pradesh in the semi-arid tropics of India. Most of the fields across all eight districts were critical in sulfur (61%–98% deficient fields); and up to six districts each in boron (83%–98% deficient fields), zinc (50–85% deficient fields), and soil organic carbon (55–97% deficient fields). Low soil organic carbon specifically indicates nitrogen deficiency. Phosphorus deficiency was critical in three districts (60–84%) while potassium in general was adequate. Soil test-based nutrient balancing through the application of sulfur, boron, and zinc in addition to farmers’ practice of adding only nitrogen, phosphorus, and potassium increased crop productivity by 8%–102%. Benefit–cost ratio (1.60–28.5) proved favourable to scale-up balanced nutrition. Better post-harvest soil health and residual benefits of sulfur, boron, and zinc up to four succeeding seasons indicated sustainability of the practice. Results showed that balanced nutrition is a way forward for sustainably improving farm productivity and livelihoods.     

Effectiveness of Gypsum and Pyrite for Sulfur Fertilization on Yield and Quality of Indian Mustard under Rainfed Conditions of North India

Field trials were conducted for two consecutive years during the rabi season in sandy loam soils of Jammu (north India) under rainfed conditions to study the effect of gypsum and pyrite for sulfur (S) nutrition on the oil content, S uptake, and yield of Indian mustard. Application of S through gypsum or pyrite either in natural or ground form increased S content, uptake, oil content, and yield of mustard significantly over the control. Among the different treatments, S application at 50 kg S ha^?1 of ground gypsum (GM₂S₂) recorded the significantly highest mean seed yield of 20.30 and 18.01 q ha^?1, which lead to an increase of 30 and 29.8% in the first and second year, respectively, over the control. For the duration of the experiment, it was observed that 25 kg S ha^?1 was the optimum dose, preferably of ground gypsum, for mustard crops under rainfed conditions.     

Optimum plant stand and nutrient doses for summer groundnut under check basin irrigation and drip fertigation in light black soils of peninsular Western India

Abstract

A field experiment was conducted at Research Farm of ICAR-Directorate of Groundnut Research, Junagadh for consecutive three summer seasons of 2013, 2014, and 2015 with the objectives of identifying optimum plant density and nutrient doses under check basin irrigation and drip fertigation for higher productivity and net returns. The treatments were; three plant densities viz., 3,33,333 plants/ha (100% of recommended plant density; P1); 4,16,666 plants/ha (125% of recommended plant density; P2), and 4,99,999 plants/ha (150% of recommended plant density;P3) in main plots, and three nutrient doses viz., 18.75–37.5–22.5 NPK kg ha^?1 (75% of recommended nutrient dose; F1), 25-50-30 NPK kg ha^?1 (100% of recommended nutrient dose; F2), and 31.25–62.5–37.5 NPK kg ha^?1 (125% of recommended nutrient dose; F3) in sub-plots, and replicated thrice. The same sets of treatments were tested under both check basin irrigation and drip fertigation. The data were analyzed using split plot design. Pod yield, haulm yield, and net returns were significantly higher with P3 as compared to P1 under check basin irrigation but only haulm yield was found significantly higher with P3 under drip fertigation. Under check basin irrigation, NH₄–N, NO₃–N, and available P and K in soil were found in the order P1?>?P2?>?P3 (p?<?0.05) while in case of drip fertigation, differences were significant only for available K which was significantly higher in P1 over both P2 and P3. Under check basin irrigation, F2 i.e., application of 100 percent of recommended nutrient doses, being at par with F3, significantly improved pod yield, haulm yield and net returns over that with F1 however, differences were not significant under drip fertigation. NH₄–N, NO₃–N and available P and K in soil under both the irrigation systems were in the order F3?>?F2?>?F1 (p?<?0.05).     

Balanced and integrated nutrient management for enhancedand economic food production: case study from rainfed semi-arid tropics in India

Soil degradation in the semi-arid tropics (SAT) is mainly responsible for low crop and water productivity. In Madhya Pradesh and Rajasthan states in India, the soil analyses of farmers’ fields revealed widespread deficiencies of S (9–96%), B (17–100%) and Zn (22–97%) along with that of P (25–92%). Soil organic C was deficient in 7–84% fields indicating specifically N deficiencies and poor soil health in general. During on-farm evaluations in rainy seasons 2010 and 2011, the soil test based addition of deficient nutrient fertilizers as balanced nutrition (BN) increased crop yields by 6–40% (benefit to cost ratios of 0.81–4.28) through enhanced rainwater use efficiency. The integrated nutrient management (INM), however, decreased the use of chemical fertilizers in BN by up to 50% through on-farm produced vermicompost and recorded yields at par or more than BN with far better benefit to cost ratios (2.26–10.2). Soybean grain S and Zn contents improved with INM. Applied S, B, Zn and vermicompost showed residual benefits as increased crop yields for succeeding three seasons. Hence, results showed INM/BN was economically beneficial for producing more food, while leading to resilience building of SAT production systems.     

Identifying critical limit in soil and plant for determining response of groundnut (Arachis hypogea) to boron application in Madurai soils of Tamil Nadu,India

To establish critical limit in soils and plant, soil samples were collected from twenty; 12, 5 and 3 soil locations of low, medium and high boron (B) status from Madurai district of Tamil Nadu, India for pot culture experiment. Based on the results of pot culture experiment, the critical limit was determined to be 42.7 mg kg^?1 for groundnut plants and 0.39 mg kg^?1 in Madurai soils. Groundnut plants were highly responded to B application in soils below the critical limit whereas soils with B greater than 0.51 mg kg^?1 did not respond. For the confirmation of pot culture results, a field experiment was conducted with different B treatments comprised of soil and foliar applications and results revealed that the pod yield of groundnut increased with increasing levels of B and the soil application of 20 kg ha^?1 as borax has showed significantly higher pod yield in the district.     

基于模式识别的半干旱区雨养春小麦干旱发生状况判别

为准确判断作物生长发育过程中农业干旱的发生状况,并预估作物产量,该研究以半干旱区1986-2011年生育期气象和产量资料为基础,分析雨养春小麦产量形成所受因素,以产量变动状况作为春小麦干旱和正常年景的判断标准。采用模式识别法,迭代求解建立可预测春小麦年景的线性分类方程,对半干旱雨养区农业干旱的发生状况进行判定。研究结果表明:半干旱雨养区春小麦产量形成受诸多因素影响。若不剔除其他因素的影响,仅以气象要素为基础无法建立判别方程,从而难以定量判断春小麦生育期农业干旱的发生状况。但在剔除播前50 cm层次土壤相对含水率大于55%的年份后,以主要生育期平均温度和降水量能够建立判别方程预测春小麦年景,从而可以对春小麦生长发育过程中的农业干旱发生状况进行定量分析。同时,5月份降水量对春小麦生长发育具有非常重要的作用,在播前50 cm层次土壤相对含水率小于55%时,只用5月份降水量一个气象要素即可较为准确地模拟估测春小麦产出。该研究可为干旱致害机理的进一步深入探讨提供参考依据。     

Sulfur,Boron, and Zinc Fertilization Effects on Grain and Straw Quality of Maize and Sorghum Grown in Semi-Arid Tropical Region of India

Experiments were conducted on-farm during two seasons (2003–2004) to determine the effects of sulfur (S), boron (B), and zinc (Zn) fertilization on the grain and straw quality of sorghum and maize grown under rainfed conditions in the semi-arid zone of India. The farmers' fields were deficient in S, B, and Zn; in addition the soils were low in organic matter and extractable phosphorus (P), but adequate in extractable potassium (K). Results showed that the applications of S, B, and Zn (SBZn) with nitrogen (N) and P (SBZn + NP) significantly increased the grain N, S, and Zn concentrations in maize and sorghum compared to farmer inputs (FI) and SBZn treatments; the results relative to P and B composition of the grain of the crops were not consistent and did not show any definite trend. The application of SBZn + NP over FI generally increased N, S, and Zn concentration in sorghum and maize straw compared to FI and SBZn treatments. The straw composition of the crops relative to P and B did not show a consistent trend. The results of this study along with the results of our earlier research demonstrate that balanced nutrition of rainfed crops not only increases yields but also enhances N, S, and Zn contents in grain and straw of these crops.     

Strategy for long term use of saline drainage water for irrigation in semi-arid regions

In arid and semi-arid regions, effluent from subsurface drainage is often saline and in the absence of a natural outlet, its disposal is a serious environmental threat. A field experiment was conducted for 7 years using drainage water of different salinity levels (EC_iw=6, 9, 12 and 18.8 dS/m) for irrigation of wheat during the dry winter season. The objective was to find whether crop production would still be feasible and soil salinity would not be increased unacceptably by this practice. The experimental crop was wheat during the winter season and pearl-millet and sorghum in the rainy season, grown on a sandy loam soil provided with subsurface drainage system. All crops were given a pre-plant irrigation with non-saline canal water and subsequently, saline drainage water of different salinity levels was used for the irrigation of wheat as per the treatment. On an average, the mean yield reduction in wheat yield at different EC_iw was 4.2% at 6, 9.7% at 9, 16.3% at 12 and 22.2% at 18.8 dS/m. Pearl-millet and sorghum yields decreased significantly only where 12 dS/m or higher salinity water was applied to previous wheat crop. The high salinity and sodicity of the drainage water increased the soil salinity and sodicity in the soil profile during the winter season, but these hazards were eliminated by the subsurface drainage during the ensuing monsoon periods. The results obtained provide a promising option for the use of poor quality drainage water for the irrigation of winter wheat without undue yield reduction and soil degradation.     

Moisture conservation for rainfed wheat production with alternative mulches and conservation tillage in the hills of north-west India

In the hills of north–west India, maize (Zea mays L.)-wheat (Triticum aestivum L.) is the dominant cropping system. However, rainfed wheat suffers from lack of optimum moisture at sowing. Field experiments were conducted for 3 years on a silty clay loam (Typic Hapludalf) to evaluate the effectiveness of mulches and conservation tillage for rainfed wheat in mitigating this problem. The treatments were ten factorial combinations of five mulch-tillage practices and two nitrogen levels (N₆₀ and N₁₂₀ kg ha⁻¹). Mulch treatments consisted of application of 10 Mg ha⁻¹ (dry weight basis), to previous standing maize, of either wild sage (Lantana camara L.) or eupatorium (Eupatorium adenophorum Sprengel) in combination with either conventional or conservation (minium) tillage prior to wheat sowing. These alternative practices were compared to the conventional farmer practice of soil tillage after harvest of maize with no mulch. The application of these weed mulches to standing maize maintained friable soil structure owing to a five fold higher mean population of earthworms underneath mulch. Mulches resulted in 0.06–0.10 m³ m⁻³ higher moisture in the seed-zone when wheat was sown compared with the conventional farmer practice of soil tillage after maize harvest. Mulch-conservation tillage treatments favourably moderated the hydro-thermal regime for growing a wheat crop. The mean root mass density under these treatments at wheat flowering was higher by 1.27–1.40 times over the conventional farmer practice during the 3 year study. Conservation tillage holds promise because it does not require elaborate tillage and may ultimately reduce animal draught in the hilly regions. Recycling available organic materials having no fodder value coupled with conservation tillage may help enrich the soil environment in the long-term. The practice also offers gainful use of these obnoxious weeds that cause great menace in grass and forest lands in the region.     

Plant analysis diagnostic indices for boron nutrition of mungbean (Vigna radiata L.) cultivars grown in a rainfed calcareous soil

Boron requirement of mungbean was assessed from yield response curves based on field experiment during 2010-11. Four cultivars, i.e., NM-11, NM-2006, Chakwal Mung-2006 and AZRI Mung-2006 were grown in a boron (B)-deficient calcareous soil by applying B at 0, 0.5, 1.0, 2.0, and 4.0 kg ha^?I. Boron application significantly increased grain yield and B uptake by all the mungbean cultivars over control. Maximum grain yield increases were: cv. NM-11, 20%; cv. NM-2006, 24%; cv. Chakwal Mung-2006, 26%; and cv. AZRI Mung-2006, 28%. The cultivars varied in B efficiency and cv. NM-11 was most B efficient (83%) while cv. AZRI Mung-2006 was the least B efficient (78%). Fertilizer B requirement (kg ha^?1) for 95% of the maximum grain yield was: 0.60 for cv. AZRI Mung-2006, 0.70 for cv. Chakwal Mung-2006, 0.75 for cv. NM-2006, and 0.85 for cv. NM-11. Plant tissue critical B concentration in leaves was higher than in seeds.     

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.     

东北典型黑土区耕地侵蚀沟形态系统分类方法构建

侵蚀沟形态分类是认识其发展现状和潜在危害的重要方法,探究耕地侵蚀沟形态分类特征和分布特征对把握耕地侵蚀沟防治重点,预防坡耕地水土流失具有重要意义。针对现有侵蚀沟形态分类体系指标获取难、分类结果不完整等问题,利用遥感解译数据,根据系统分类和信息科学理论,结合东北黑土区现实需求,构建了耕地侵蚀沟系统分类方法,并在典型黑土耕作区海伦市进行了验证。结果表明：1）海伦市耕地侵蚀沟具有小面积、大宽度、短长度的特点,Ⅰ类和Ⅱ类为数量最多的一级分类;Ⅱ类四等微型沟（Ⅱ4T）和Ⅱ类四等小型沟（Ⅱ4S）在二级和三级分类中数量居多,易通过高标准农田建设进行治理。2）地形要素下耕地侵蚀沟形态分布差异明显,需要特别关注在高程180～<240 m,坡长35～<55 m,坡度2°～6°,西南坡区域内的Ⅰ4T、Ⅱ4S、Ⅱ4T等发育程度较低的侵蚀沟向更高发育程度的Ⅳ4M、Ⅴ4M等类型转变,建议结合农田建设及时采取综合防治措施,以防止耕地侵蚀沟的潜在破坏。3）构建的“类+等+型”耕地侵蚀沟分类定级方法,兼顾指标的易获取性和方法的易操作性,能够精准、直观地揭示耕地侵蚀沟的形态特征及其危害情况,可为侵蚀沟和黑土耕地的协同综合治理提供方法借鉴。     

Estimation of a reliable evapotranspiration model and crop coefficient in red gram ( Cajanus cajan L .) for semi-arid environments in India

The study aims to compute the reference evapotranspiration (ETo) by six standard methods such as Penman Monteith, Modified Penman, Hargreaves, Radiation Balance, Blaney Criddle and Pan Evaporation by using the meteorological data of the All India Coordinated Research Project on Water Management at Rahuri, India (long. 74° 18′, lat. 19° 45′). These methods were compared with lysimeter crop evapotranspiration (ETc) by statistical tools. The results revealed that the total lysimeter ETc of red gram in 132 days' growing period (sowing to harvest) was 494?mm and the ETo in the above-mentioned models were 485.2, 486.9, 544.6, 547.6, 563.9 and 485.2?mm, respectively. Out of six models, ETo of Modified Penman and Pan Evaporation methods were very much close to lysimeter ETc, but the coefficient of variation was very high, i.e., 43.05% and 23.91%, respectively. But in the Hargreaves and Blaney Criddle methods, the coefficient of variation was low, i.e., 15.97% and 12.6%, respectively. Besides low coefficient of variation, these two methods require limited meteorological parameters such as minimum and maximum temperature, radiation. For generating these parameters even at regional level, minimum expenditure is involved. The crop coefficient (Kc) estimated by Hargreaves (Kc 0.90) and the Blaney Criddle (0.87) model for the entire growing season was very much close to the Food and Agricultural Organization (FAO) 56 model, and this can be used for estimating the irrigation requirement of red gram.     

Diversification of rice (Oryza sativa L.)-based cropping systems for higher productivity,resource-use efficiency and economic returns in south Gujarat,India

The continuous growing of rice has led to a deterioration in soil quality, resulting in a serious threat to agricultural sustainability in the high rainfall zone of south Gujarat, India. Therefore, crop diversification with a wider choice in the production of crop varieties is being promoted to restore the soil quality. A field experiment was conducted in Navsari, India during 2003–2007 on a Vertisol to evaluate the productivity, sustainability, resource-use efficiency and economics of 10 rice-based cropping systems. The results showed that system productivity for rice–fenugreek (Trigonella foenum-graecum)–okra (Abelmoschus esculentus) was highest (25.73 t ha^?1), followed by rice–onion (Allium cepa)–cowpea (Vigna sinensis L.) (24.15 t ha^?1); and the lowest system productivity was observed with the rice–wheat (Triticum aestivum)–fallow system (7.85 t ha^?1). The sustainable yield index (0.97), production efficiency (102.94 kg ha^?1 day^?1) and field water use efficiency (15.98 kg ha^?1 mm^?1) were maximum with the rice–fenugreek–okra system. Similarly, net return (96,286 Rs ha^?1), net return per rupee invested (2.83 Rs), monetary production efficiency (385.14 Rs ha^?1 day^?1) and water use efficiency (59.80 Rs ha^?1 mm^?1) were maximum with the rice–fenugreek–okra cropping sequence. There were significant effects of various cropping sequences on available nitrogen, phosphorus, potassium and organic carbon content in the soil. Overall, the rice–fenugreek–okra system was found to be the most productive, sustainable, resource-use efficient and remunerative cropping system, followed by the rice–onion–cowpea system.