Soil-Test-Based Balanced Nutrient Management for Sustainable Intensification and Food Security: Case from Indian Semi-arid Tropics

In the semi-arid tropics (SAT), there exists large yield gaps (two- to four-fold) between current farmers’ yields and achievable yields. Apart from water shortages, soil degradation is responsible for the existing gaps and inefficient utilization of whatever scarce water resource is available. On-farm soil fertility testing across different states in Indian SAT during 2001–2012 showed widespread new deficiencies of sulfur (46–96 percent), boron (56–100 percent), and zinc (18–85 percent) in addition to already known phosphorus (21–74 percent) and nitrogen (11–76 percent, derived from soil carbon). Based on these results, a new fertilizer management strategy was designed to meet varying soil fertility needs at the level of a cluster of villages by applying a full nutrient dose if >50 percent fields were deficient and a half dose in the case of fields <50 percent deficient. Improved nutrient management significantly increased crop productivity in groundnut (Arachis hypogaea) (17–86 percent), sorghum (Sorghum bicolor) (30–55 percent), soybean (Glycine max) (10–40 percent), and maize (Zea mays) (10–50 percent) with favorable benefit-cost ratios (1.43–15.2) over farmers’ practice. Nutrient balancing improved nitrogen-fertilizer-use efficiency in respect of plant uptake from soil, transport into grain, use efficiency in food production, and grain nutritional quality. Balanced-nutrient-managed plots showed better postharvest soil fertility. Residual benefits of sulfur, boron, and zinc were observed in up to three succeeding seasons. Results of soil-test-based nutrient-management trials have sensitized policy makers in some states for desired policy orientation to benefit millions of smallholders in the Indian SAT.     

Balanced Nutrient Management for Crop Intensification and Livelihood Improvement: A Case Study from Watershed in Andhra Pradesh,India

Soil health assessment of farmers’ fields in watershed villages in Medak district, Andhra Pradesh, India showed widespread deficiencies of sulfur (S), boron (B), and zinc (Zn) in addition to organic carbon and phosphorus (P). Participatory on-farm trials on soil test-based application of deficient Zn, B, and S along with nitrogen (N) and P during 2009 to 2012 significantly increased crop yields over farmers’ practice (FP)—by 31% to 45% in chickpea, 15% to 16% in cotton, 12% to 15% in paddy, and 8% to 9% in sugarcane. Total soluble sugars in sugarcane under balanced nutrition (BN) increased by 13%. Residual benefits of S, B, and Zn were observed in succeeding chilly crop (12% higher yield). Benefit to cost (B:C) ratios of BN ranged between 2.8 to 8.5 in chickpea, 2.6 to 4.4 in cotton, 2.3 to 2.9 in paddy, and 7.1 to 11.4 in sugarcane, indicating economic feasibility for scaling-up.     

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.     

Alleviation of Multinutrient Deficiency for Productivity Enhancement of Rain-Fed Soybean and Finger Millet in the Semi-arid Region of India

Soil nutrient contents were determined in 802 surface soil samples (0–15 cm deep) collected from farmers' fields that support extensive cultivation of soybean (Glycine max L.) and finger millet (Eleusine coracana G.), spread across three districts, in the semi-arid regions of Karnataka, India. Following soil analysis, on-farm crop trials were conducted during 2005–2007 to study the crop response to the soil application of nitrogen (N), phosphorus (P), sulfur (S), boron (B), and zinc (Zn) fertilizers. Analyses of soil samples revealed that 4–83% fields were deficient in N, 34–65% in P, 83–93% in extractable S, 53–96% in B, and 34–88% of farmers' fields were deficient in Zn. On-farm trials conducted during the three rainy seasons (2005, 2006, and 2007) significantly (P ≤ 0.05) enhanced crop productivity indices such as yields of grain, stover, and total biomass in soybean and finger millet crops. Integrated management of deficient nutrients in finger millet and soybean crops significantly enhanced the grain and straw uptake of N, P, K, S, and Zn.     

Widespread Deficiencies of Sulfur,Boron, and Zinc in Indian Semi-Arid Tropical Soils: On-Farm Crop Responses

On-farm studies were conducted during 2002–2004 to determine fertility status, including sulfur (S) and micronutrients, and crop response to fertilization on farmers' fields in the semi-arid zone of India. Nine hundred-twenty four soil samples taken from farmers' fields, spread in the three districts of Andhra Pradesh (India), were analyzed for soil chemical fertility parameters. Results showed that samples were low in organic carbon (C), total nitrogen (N), and low to moderate in extractable phosphorus (P), but adequate in available potassium (K). Analyses of soil samples for extractable S and micronutrients was most revealing and showed that 73–95% of the farmers' fields were deficient in S, 70–100% in boron (B), and 62–94% in zinc (Zn). On-farm trials conducted during three seasons (2002–2004) showed significant yield responses of maize, castor, groundnut, and mung bean to the applications of S, B, and Zn. The yield responses were larger when S, Zn, and B were applied along with N and P. Applications of S, B and Zn also significantly increased the uptake of N, P, K, S, B, and Zn in the crop biomass. Results show widespread deficiencies of S, B, and Zn under dryland agricultural conditions; results also show that the nutrient deficiencies can be diagnosed by soil testing. It was concluded that the drylands in the semi-arid regions of India were not only thirsty (water shortage), but also hungry (nutrient deficiencies).     

Low-cost interventions for big impacts in dryland production systems

A study at selected action sites in semi-arid region of Andhra Pradesh, India, showed widespread land degradation due to low levels of soil organic carbon (78% of fields) and deficiencies of available nutrients like phosphorus (34%), sulfur (93%), calcium (33%), zinc (84%), boron (73%), and copper (33%). Soil test-based addition of deficient micro- and macronutrients increased food grain production by 30–40% and straw (which is used as fodder) production by 10–30%. Micro-watershed scale low-cost cement-lined farm-ponds at smallholder farm level proved a scalable technology for drought-proofing of crops resulting into additional crop yield by more than 30% during 2015. Augmentation of water sources also facilitated farmers’ to successfully diversify the production system. Shared machinery resources improved the operational and economic efficiency of farm sowing operations through higher crop yields by around 10%. We conclude that a mix of low-cost critical interventions if out-scaled in a large number of dryland small holdings through policy support may not only improve productivity and livelihoods, but also enhance their abilities to effectively cope with the climatic aberrations.     

Integrated Plant Genetic and Balanced Nutrient Management Enhances Crop and Water Productivity of Rainfed Production Systems in Rajasthan,India

Analysis of soils from 421 farmers’ fields in eastern districts of Rajasthan, India, revealed widespread deficiencies of sulfur (S; 43 to 87% fields deficient), boron (B; 25 to 100%), and zinc (Zn; 0 to 94%) in addition to phosphorus (P; 10 to 73%) and soil organic carbon (1 to 84%). An integrated approach of application of deficient S, B, and Zn along with N and P to high-yielding crop cultivars increased yield over farmers’ practice of N and P application to local cultivars by 92 to 204% in maize, 115 to 167% in pearl millet, and 150% in groundnut. Benefit-to-cost ratio of the integrated strategy varied from 3.33 to 8.03 in maize, 2.92 to 3.40 in pearl millet, and 1.15 in groundnut. The integrated approach effectively utilized scarce water in food production and increased rainwater-use efficiency at 67 to 145 kg mm^?1 ha^?1 from 21 to 50 kg mm^?1 ha^?1 under farmers’ practice.     

平衡施肥对白浆土水稻产量及品质的影响

通过土壤测试、田间试验和品质分析,明确了三江平原桦川县创业乡丰年村白浆土养分供应状况和水稻平衡施肥效果。结果显示,该土壤98.4%缺氮,76.6%缺磷,97.7%缺钾,72.7%缺锌,35.9%缺硼。与最佳处理(OPT)相比,不施氮肥减产26.2%,不施磷肥减产12.1%,不施钾肥减产10.3%,不施锌肥减产24.2%,不施肥(CK)减产39.9%。与OPT处理相比,不施氮肥、磷肥、钾肥、锌肥、硼肥和CK的经济效益分别降低3936、1774、1527、4070、886和5643元/hm2。平衡施肥(OPT)与农民习惯施肥(FP)相比增产20.3%,经济效益增加3283元/hm2,粗蛋白含量增加0.13个百分点,直链淀粉含量降低0.84个百分点,胶稠度增加1.7 mm,对改善稻米品质有积极作用。     

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.     

Soil–Plant Nutrient Status and their Relations in Maize-Growing Fields of Wolaita Zone,Southern Ethiopia

This study investigates the soil–plant nutrient status and relationship in Wolaita, Southern Ethiopia. Maize leaves, soil samples and field history were collected. The result indicated that continuous cultivation without fallowing, complete crop residue removal and inadequate fertilization were common practices. The soil was low in organic carbon, total nitrogen, available phosphorus, potassium, sulfur, boron and copper. Tissue analysis indicated 100, 84, 54 and 28% deficiency of nitrogen, phosphorus, potassium and copper, respectively. Significant and positive correlations (r = 0.70, 0.40 and 0.50) of soil phosphorus, calcium and copper with tissue content were observed. Soil pH was correlated with tissue phosphorus (r = 0.4), iron (r =—0.3) and manganese (r = ?0.7). Overall, the levels of calcium, magnesium, iron, manganese and zinc were adequate for maize. Therefore, fertilizer application addressing nitrogen, phosphorus, potassium and copper deficiencies is recommended for the study area.     

Mineralogy and Fertility Status of Selected Soils of the Eastern Cape Province,South Africa

Abstract

Thorough knowledge of cultivated soils is necessary for their informed and sustainable management. This study was carried out to gain a better understanding of cropped soils in the Eastern Cape Province of South Africa. The mineralogical and chemical composition and nutrient status of topsoils collected from homestead gardens and fields of smallholdings in 5 of the 36 magisterial districts where smallholder farming prevails in the Province were determined. These data were supplemented with results of soil analyses conducted by an Analytical Services Laboratory that obtains its samples from the 31 magisterial districts where large‐scale farms are dominant. The soils studied were similar mineralogically, and all had a clay fraction that was dominated by quartz, mica, and/or kaolinite, which is fairly typical for many tropical and subtropical soils. Elemental analysis showed that the soils were generally low to very low in their total content of nutrients, except for sulfur (S), manganese (Mn), zinc (Zn), copper (Cu), and boron (B), reflecting the marine and sedimentary nature of their parent materials. The available nutrient status of the cultivated soils was generally low to very low, especially those found in smallholder fields. This was attributed to low soil organic matter levels and low geological reserves of some nutrients notably phosphorus (P), potassium (K), and calcium (Ca), coupled with continuous cultivation of the lands without adequate nutrient replenishment. Depending on location, 75–100% of the fields tested low in pH, 62–100% were low in organic carbon, 83–100% were low in extractable K, 62–93% were low in extractable Ca, and 79–100% were deficient in available phosphorus. The nutrient status of soils receiving moderate to high amounts of nutrients was generally satisfactory, as revealed by the nutrient content of garden soils found on smallholdings and the fields on large‐scale farms. In all cases, soil pH was low to critically low. The findings are used to propose a soil fertility management strategy for the communal areas of the Province.     

Diagnosis of Secondary and Micronutrient Deficiencies and Their Management in Rainfed Agroecosystems: Case Study from Indian Semi‐arid Tropics

Rainfed agriculture in the semi‐arid tropical (SAT) regions of India is greatly influenced by water shortages caused by low, highly variable, and erratic rainfall. However, apart from water shortages, crop productivity in these regions is also affected by low fertility. Little effort has been devoted to diagnosing and managing the nutrient‐related problems in farmers' fields in the SAT regions of India. The ongoing integrated watershed management program by the International Crops Research Institute for the Semi‐arid Tropics and its partners provided the opportunity to diagnose the soil infertility‐related problems by soil testing, develop nutrient management protocols, and determine on‐farm crop responses to fertilization in the SAT zone of India. This article discusses examples from recent research on the diagnosis of multinutrient deficiencies and on‐farm crop responses to fertilization. Results of analyses of soil samples from farmers' fields in several districts of Andhra Pradesh, Karnataka, Tamil Nadu, Rajasthan, and Madhya Pradesh states and Junagarh district, Gujarat, showed that almost all farmers' fields had low organic carbon (C), low to moderate available phosphorus (P), and generally adequate extractable potassium (K). However, the widespread deficiencies of sulfur (S), boron (B), and zinc (Zn) were most revealing; their deficiencies varied with nutrient, district, and state. On‐farm trials conducted during three seasons (2002–2004) in three districts of Andhra Pradesh showed significant yield responses of maize, castor, groundnut, and mung bean to the applications of S, B, and Zn over farmer's input treatment, and the yield responses were larger when these nutrients were added along with nitrogen (N) and P. It is concluded that the deficiencies of nutrients such as S, B, and Zn are widespread and are holding back the potential of rainfed production systems. Clearly, nutrient deficiencies can be diagnosed by soil testing.     

Diagnostic Leaf Nutrient Norms and Identification of Yield-Limiting Nutrients of Mango in Eastern Plateau and Hill Region of India

The leaf nutritional status of mango orchards was assessed using diagnosis and recommendation integrated system (DRIS). The DRIS norms, which showed higher variance and lower coefficients of variation, are found to have greater diagnostic precision. As per DRIS indices, a relative deficiency for magnesium, zinc, and boron corresponding to relative sufficiency for calcium, nitrogen, phosphorus, sulfur, and potassium was detected in 9-year-old mango orchards. For the younger orchards (6–7 year old), the order of requirement of nutrients was found to be calcium > sulfur > potassium > boron > nitrogen > phosphorus > magnesium > zinc. Boron was found as the most yield-limiting elements in all age group of plants. When the DRIS indices were compared on the basis of soil pH, calcium and magnesium were most yield-limiting nutrients below pH 5.5, while nitrogen, zinc, and boron were found to be most limiting above pH 5.5.     

磷钾硼锌肥对百合、白术产量和养分吸收的影响

在田间试验条件下研究了不同营养元素对百合、白术产量和养分吸收的影响。两年结果表明,在河沙土和灰泥土上,施用磷、钾、硼和锌肥的百合产量分别平均增产5.1%、33.5%、22.3%、16.3%和16.2%、12.5%、2.1%、6.1%,在灰泥土上,白术产量分别平均增产8.6%、34.6%、9.1%、5.8%,百合施用钾、硼和锌肥的增产效果大于白术,而白术施磷的增产效果大于百合。施磷肥能促进百合和白术对氮、磷、钾和硼的吸收,而降低对锌的吸收;施钾、硼和锌肥能增进百合和白术的氮、磷、钾、硼和锌养分的吸收量。百合和白术吸收的养分量表现出钾>磷>锌>硼。百合和白术吸收的氮、磷、钾和锌主要分配在鳞茎和根状茎部分,吸收的硼主要集中在茎叶部分。平衡施肥可提高药用部分(鳞茎和根状茎)的磷、钾和锌养分的分配比率。     

Capsicum annuum var. annuum under macronutrients and boron deficiencies: Leaf content and visual symptoms

This study aims to describe macronutrient and boron deficiencies in pepper grown in a hydroponic system in the presence of a substrate during the vegetative and fruiting phases. The experiments were carried out into a greenhouse, and consisted of a randomized block design with eight treatments: complete solution (control) and nitrogen (-N), phosphorus (-P), potassium (-K), calcium (-Ca), magnesium (-Mg), sulfur (-S) and boron (-B) deficient solutions, with four repetitions for each assay. Visual diagnoses of certain macronutrient and boron deficiencies can be applied by farmers to aid in soil management, since they are observed in leaves, while N, P, Ca, S and B deficiencies led to roots symptoms. Pepper fruits showed nutritional deficiency symptoms when grown under N, K, Ca, Mg, S and B deficits. The appearance of nutrient deficiency symptoms in pepper plants occurs in the following order: N, K, P, Mg, S, Ca and B.     

Soil Test and Plant Tissue Analysis as Diagnostic Tools for Fertilizer Recommendations for Cassava in an Ultisol

Soil- and plant-based fertilizer recommendations hold promise for increasing farmers’ incomes with high-input crops such as cassava. Considering the significance of cassava for the food, nutritional, and economic security of a half billion people globally and the positive response of the crop to fertilizer and manure applications in terms of tuber yield and quality through starch improvement and cyanogenic glucoside reduction, these recommendations were validated and popularized in two districts of Kerala State. Soil and plant samples from nine major cassava-growing districts of Kerala were analyzed for soil reaction, organic carbon, and essential nutrients, which formed the basis for the recommendation. The soil-test-based recommendation [nitrogen (N)–phosphorus (P)–potassium (K)–zinc (Zn) at 82:6.3:68:2 kg ha^?1 along with farmyard manure (FYM) at 6.25 t ha^?1] resulted in the greatest benefit–cost ratio of 1.75 with improvements in tuber and soil quality.     

Stretching Soil Sampling to Watershed: Evaluation of Soil‐Test Parameters in a Semi‐arid Tropical Watershed

Soil sampling is an integral component of fertility evaluation and nutrient recommendation for efficient use of nutrients in crop production. Little attention has been devoted to evaluating methodology for sampling watersheds under dryland agriculture. A stratified random sampling methodology for sampling the Appayapally watershed in Mahabubnagar district of Andhra Pradesh state in the semi‐arid tropical region of India was adopted and evaluated. The watershed has an area of about 500 ha, with gentle sloping lands (<1% slope), and 217 farmers own land in the watershed. The soils are Alfisols. A total of 114 soil samples were collected from the top 15‐cm layer to represent the entire watershed. Each sample was a composite of 7–8 cores, randomly collected from the area represented by a crop and group of farmers. The soil samples were air dried, ground, and analyzed for pH, electrical conductivity (EC), organic carbon (C), total nitrogen (N), and extractable phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), sodium (Na), sulfur (S), zinc (Zn), manganese (Mn), iron (Fe), copper (Cu), and boron (B). Statistical analysis of the results on soil fertility parameters showed that the mean‐ or median‐based results of soil tests performed in the study did not differ significantly when the sample set size varied from 5 to 114 (100% of the population). Our results indicate that farmers' fields in the Appayapally watershed are uniform in the chemical fertility parameters studied, and even a small sample set size can represent the whole population. However, such a sampling strategy may be applicable only to watersheds that are very gently sloping and where fertilizer use is very low, resulting in an overall low fertility in the whole watershed.     

安徽省土壤有效硫现状及时空分布

【目的】 土壤有效硫是作物硫素营养的主要来源,在获取省域范围耕地土壤有效硫基础数据和硫肥试验研究结果的基础上,以地统计学特征分析和新的土壤有效硫分级指标统计为手段,研究全省土壤有效硫时空变化特点和区域性分布现状,掌握全省耕地土壤硫养分丰缺状况及供给水平,为科学施肥提供依据。 【方法】 选择安徽省砂姜黑土、潮土、黄褐土、水稻土等11个土类,采集农田0—20 cm耕层土样34.5万个。通过大样本数据的统计分析,利用ArcGIS进行Kriging插值的地统计学分析,按照本省耕地土壤有效硫新的丰缺分级标准,即极缺 (< 10.0 mg/kg)、缺乏 (10 ～16 mg/kg)、较缺乏 (16～22 mg/kg)、中等 (22～34 mg/kg) 和丰富 (> 34 mg/kg) 五级,结合第二次土壤普查分级指标对应分析,进行省域耕地土壤有效硫丰缺现状和时空分布研究。 【结果】 1) 全省耕地土壤有效硫含量范围在0.10 ～101.90 mg/kg之间,平均值为24.99 mg/kg,中位数为21.00 mg/kg。2) 全省耕地土壤缺硫概率较大。有效硫含量处于极缺 (< 10 mg/kg)、缺乏 (10 ～16 mg/kg) 与较缺乏 (16 ～22 mg/kg) 水平的分别占总样本数的13.76%、20.91%和18.43%。3) 省域总体缺硫状况由东向西递增、南北向中间趋减。按不同农业区域比较,淮北平原的宿州、亳州和阜阳市缺硫最严重,其次是皖南山区,又以黄山市、铜陵市土壤缺硫较严重。4) 土壤类型和时空变化上,以棕壤、黄潮土、粗骨土、红壤、黄壤、紫色土和砂浆黑土等缺硫最为严重。与20年前研究分析比较,沿江平原、江淮丘陵和皖西农区缺硫趋势减弱,而皖南山区土壤缺硫状况明显加重。目前,棕壤、砂姜黑土和黄棕壤缺硫频率和风险增大,而黄潮土、黄褐土和灰潮土缺硫频率降低。 【结论】 省域耕地缺硫 (< 22 mg/kg) 面积约311.19 × 104 hm2,占全省耕地总面积的53.10%。针对棕壤、砂浆黑土、黄潮土、红壤等九类土壤缺硫比率高 (39.67% ～56.89%之间) 的现状,应推荐含硫化肥或补施硫肥,降低作物缺硫风险。      

Efficacy of Potassium Humate and Chemical Fertilizers on Yield and Nutrient Availability Patterns in Soil at Different Growth Stages of Rice

Potassium humate (PH) is a promising natural resource to be utilized as an alternative for increasing crop production. A pot experiment was conducted during 2009 and 2010 to assess the efficacy of application of potassium humate (0, 5, and 10 mg kg^?1 soil) alone and in combination with chemical fertilizers (75% and 100% recommended dose of nitrogen–phosphorus–potassium) on yield and nutrient availability patterns in soil at different growth stages of rice. Two doses of zinc, viz. 0 and 12.5 mg kg^?1, were also applied. Sole and combined application of potassium humate with nitrogen–phosphorus–potassium (NPK) and zinc significantly (p < 0.05) improved the yield and availability of nitrogen, phosphorus, potassium, sulfur, zinc, and dehydrogenase activity in soil. Application of 10 mg kg^?1 potassium humate along with 100% NPK and 12.5 mg kg^?1 zinc sulfate proved significantly superior when compared to 75% and 100% of NPK alone.