Soil Testing as a Tool for On-Farm Fertility Management: Experience from the Semi-arid Zone of India

Rainfed agriculture in the dry regions is affected by water shortages. Our earlier research showed that the deficiencies not only of major nutrients but also those of sulfur (S) and micronutrients are holding back the potential of agricultural production systems. The objectives of this article are to discuss the efficacy of soil testing to diagnose nutrient deficiencies using 28,270 diverse soil samples collected from farmers' fields in the semi-arid tropical (SAT) regions of India and to confirm the efficacy of the soil test-based balanced nutrient management in enhancing productivity of a range of crops in on-farm farmer participatory trials under rainfed conditions. Results of a large numbers of on-farm trials demonstrated that soil testing is indeed an effective tool for on-farm fertility management, a prerequisite for sustainably enhancing the productivity in rainfed areas in the SAT regions of India. The need to strengthen the soil-testing infrastructure in the country is emphasized.     

泥石流灾害防治方案优选模型

以陕北府谷三道沟矿区泥石流灾害防治工程为例,选取安全可靠性、环境协调性、经济合理性、设计规范性、施工复杂性、后期维护性等评价指标,提出基于熵权决策法的定量因素权重确定方法,建立泥石流防治方案比选模型。通过专家打分法建立原始判断矩阵,利用熵权法得到的熵值与属性矩阵确定理想矩阵,根据汪氏贴近度及欧氏贴近度计算待选方案评价指标与理想矩阵的贴近度来确定方案的优劣次序。结果表明,方案三(消能坝+Ⅰ型排导渠+停淤场)为最优方案。该比选模型在传统主观定性确定权重基础上定量确定评价指标权重,克服了权重确定主观随意性,提高了计算过程与结果的客观性及准确性,具有一定的理论意义和应用价值。     

基于Logistic-CA-Markov模型的快速城市化地区土地利用结构变化研究

研究快速城市化地区土地利用结构的变化并预测其未来发展趋势,可以为区域土地合理利用与配置提供参考。利用Logistic-CA-Markov耦合模型研究无锡市2000—2010年的土地利用结构变化,探讨其驱动因子,并区分目前趋势发展、生态环境保护和综合发展3种情景,对研究区2020年土地利用结构进行模拟和预测。结果表明,10 a间无锡市建设用地增加了近一倍,主要来源于耕地;目前趋势发展情景下建设用地扩张仍明显,生态环境保护情景下建设用地不再增加,而综合发展情景下建设用地略有增加,耕地等地类减少不明显。对于无锡市这样的快速城市化地区而言,综合发展情景的模拟结果是比较理想的。     

Evaluating Plant Species-Specific Contributions to Nutrient Mitigation in Drainage Ditch Mesocosms

Eutrophication of surface water bodies is a worldwide concern. In the USA alone, excessive nutrients are blamed for nearly 5,700 impairments of surface water bodies. Innovative measures, such as maximizing drainage ditch nutrient retention, are being examined to decrease the amount of nitrogen (N) and phosphorus (P) running off agricultural lands and into aquatic receiving systems. The goal of this experiment was to measure the nutrient mitigation ability of six aquatic plants typically found in agricultural drainage ditches in the lower Mississippi River Basin. Experimental mesocosms (1.25?×?0.6?×?0.8 m) were filled with sediment and planted with monocultures of one of six obligate wetland plant species (Typha latifolia (broadleaf cattail), Panicum hemitomon (maidencane), Thalia dealbata (powdery alligator-flag), Echinodorus cordifolia (creeping burhead), Myriophyllum spicatum (Eurasian watermilfoil), and Saururus cernuus (lizard??s tail)), while three replicates were left non-vegetated to serve as controls. Mesocosms were amended with 5 mg?L^?1 (each) of nitrate, ammonia, dissolved inorganic phosphorus, and total inorganic phosphorus, while nitrite amendments (1 mg?L^?1) were also made over a 4-h hydraulic retention time. Following the 4-h exposure, ??clean?? (non-amended) water was flushed through mesocosms for an additional 8 h to assess residual leaching of nutrients. Outflow water concentrations and loads decreased for all examined forms of N and P. In certain cases, there were significant differences between plant species; however, for the majority, there was no statistical difference in percent decrease between plant species. While native aquatic vegetation shows promise for mitigation of nutrient runoff, further studies altering the hydraulic retention time for improved efficiency should be conducted.     

基于AHP的土地集约利用水平模糊综合评价

探讨AHP与模糊理论相结合的方法在土地的集约利用评价中的运用,提出了基于AHP的土地集约利用的模糊综合评价方法,为土地的集约利用评价提供一种精确方法。以河北省为例,与北京市、湖南省、黑龙江省、甘肃省的实际数据,建立土地集约利用评价指标体系,运用AHP确立了各评价指标的权重。并对AHP的判断矩阵进行了一致性检验,针对土地集约利用评价的特点,确立了各指标对土地集约利用评价的隶属度函数,在此基础上,运用模糊综合评价方法,对不同地区的土地集约利用水平进行综合评价。结果表明：河北省土地的集约利用总体水平居全国中上等水平,其土地利用结构合理性指标和土地利用程度指标居全国的中上等水平,而土地投入强度指标不高,土地使用的效果指标略差。通过研究结果可靠性分析证实,基于AHP的模糊综合评价是进行土地集约利用评价的可靠方法。     

Review of Integrated Nutrient Management for Sustainable Crop Production

This study analyses the influences of sociodemographic factors, business orientation of farmers, and farm characteristics on adoption of ICT-based information through primary data collected from 461 farmers in eight districts of Uttar Pradesh, India. A personal interview survey was conducted using a pre-tested structured questionnaire. The Poisson Count Regression Model was used to analyze the factors influencing use of the information derived through ICT-based systems on various agricultural practices. The findings indicate that education, income, and social category of farmers are important sociodemographic factors affecting the adoption of ICT-based information systems. Similarly, farmers who consider farming as a business venture, practice a diversified cropping system, and have small farms are more likely to use ICT-based information.     

Composting and Evaluating a Pulp and Paper Sludge for Use as a Soil Amendment/Mulch

Composting could be used in the pulp and paper industry to treat primary sludges as an alternative to landfilling. The objective of this project was to compost and evaluate a pulp and paper sludge for use as a soil amendment/mulch. Primary sludge, tailings, wood ash (0, 5 or 10 percent by volume), and paunch (cattle stomach contents and tissue) from a slaughterhouse were composted in a 91 m windrow that was turned one to two times per week. The pile moisture content and temperature were controlled at 50 percent and 57–63°C during 14 weeks of composting. The compost was then cured for 4 weeks for a total treatment time of 18 weeks. Sludge dry mass decreased by approximately 50 percent, pH increased slightly to 8.2 to 8.5, and carbon-nitrogen ratio decreased from 270:1 to 14–67:1 after composting and curing. Electrical conductivity of all final composts was over 4 dS/m. Shoot biomass of tomato plants grown in a compost-amended medium (50 percent compost, 25 percent sand, 25 percent perlite by volume) improved with composting time but was still only 35–65 percent that of plants grown in a peat moss-amended medium (control). Shoot weight and height of poplar plants grown in soil amended with aged compost were unaffected by compost application rate (incorporated or as a mulch) at less than or equal to 180 Mg/ha. In summary, this study demonstrated that a pulp and paper sludge and wood ash mixture yielded a compost that could be used as a low quality mulch or soil amendment for poplar.     

Application of QUEFTS Model for Site-Specific Nutrient Management of NPK in Sweet Potato (Ipomoea batatas L. Lam)

Sweet potato productivity in India is either stagnated or lowering down over the past many years. The main reasons for low yield are conventional blanket recommendation of fertilizers, lower nutrient-use efficiency and imbalance in the use of fertilizers. Recommendation of major nutrients, nitrogen, phosphorus, and potassium (NPK), based on quantitative approaches will augment sweet potato production per unit area by increasing the nutrient-use efficiency. The present study calibrated the Quantitative Evaluation of Fertility of Tropical Soils (QUEFTS) model for the estimation of NPK requirements and fertilizers recommendations for different target yields of sweet potato. The QUEFTS basically works on the principle of NPK nutrient interactions and climate-adjusted yield potential of a region. Published data sets from several field experiments related to NPK carried out till date were collected to reflect the environment variability. The results of the present study showed that to produce one ton tuber, 16:6:18 kg N, P, and K, respectively, would be needed with the internal efficiencies of 61:167:57 kg tubers kg^?1 NPK removed. The maximum accumulation and dilution (kg tuber kg^?1 nutrient removed) of N (40, 80), P (96, 272), and K (30, 85) were also derived as standard parameters in QUEFTS for optimum fertilizer recommendation in tropical and subtropical regions of India. The observed yields of sweet potato with different amounts of nutrients were in agreement with the values predicted by the model. Therefore, it is utmost important to have the results of the study validated in major growing environments of India for fertilizer recommendation in sweet potato.     

Technology Transfer Model on Integrated Nutrient Management Technology for Sustainable Crop Production in High-Value Cash Crops and Vegetables in Northwestern Himalayas

Balh Valley in the northwestern Himalayas in India is well known for cultivation of high-value cash crops and vegetables. The Indo-German Agricultural Project executed four decades ago in the valley has been the driving force for agrarian development in the valley, but crops are still grown under nutrient-starved conditions, giving low productivity compared to national averages. To demonstrate and disseminate the integrated nutrient management (INM) technology in the irrigated ecosystem of Balh Valley, efforts were funded by the Indian Farmers' Fertilizers Cooperative Limited (IFFCO) to develop sustainable crop production systems under cash crops and vegetables following an appropriate technology transfer model by Krishi Vigyan Kendra (KVK), Sundernagar, India. For effective technology transfer, field demonstrations, method demonstrations, farmers' training camps, field days, and numerous field conventions were organized in addition to extending soil testing, literature supply, promotional seed and fertilizer input supply, and training of agro-cooperative society personnel who deal with seed and fertilizer input supply in the region. The greater extension gaps in tomato–blackgram and potato–Kharif onion crop sequences indicated need for effective technology transfer tools for high adoption of technology in these production systems in the valley. Potato–Kharif onion cropping system using INM technology resulted in greater system productivity in terms of blackgram equivalent yield (76.7q ha^?1) and gross (3,06,920 ha^?1) and net returns (2,22,295 ha^?1), followed by tomato–blackgram and green pea–okra production systems, respectively, using an appropriate technology transfer model. The study also revealed improvement in available nitrogen (N)–phosphorus (P)–potassium (K) and organic carbon (C) pool of the soils besides crop productivity and profitability in field trials under INM practices over farmers' practiced plots. Knowledge before the study about soil testing, dose and time of application of organics, chemical fertilizers, and their integrated use ranged from 9 to 41%, whereas knowledge increases after the study ranged between 55 to 88%. The INM technology adoption rate after 1 year of project completion ranged between 66 to 70%, whereas soil testing was done by only 35% of farmers. Thus, INM technology adoption rate was greater following the appropriate technology transfer model based on critical analyses of fertilizer use, existing production systems, and appropriate interventions for technology transfer. This comprehensive study under the IFFCO-KVK Collaborative Project attempts to highlight that an effective technology transfer model can play a key role in adoption of INM technology for sustainable production systems in the developing world, especially for resource- and knowledge-poor farmers of collateral socioagroeconomic environments of developing nations.     

Integrated Nutrient Management Affects Fruit Yield of Sapota (Achras zapota L.) and Nutrient Availability in a Vertisol

ABSTRACT

We studied the effect of integrated nutrient management (INM) combinations on supplement of plant nutrient for quantitative and qualitative fruit production in sapota. Thus, 17 combinations of INM practices were evaluated on fruit yield of sapota and nutrient availability in a Vertisol of Chambal region, India. The results demonstrated that almost all treatment combinations comprised of recommended dose of fertilizer (RDF), i.e. 1,000:500:500 g NPK plant^?1 with application of organic and inorganic sources of nutrients had a significant effect on the fruit yield of sapota, soil microbial biomass, NPK content of leaf, fruit and soil over control (T₁). Among different treatments, application of 2/3rd part of RDF + 50 kg FYM + 250 g Azospirillum + 250 g Azotobacter plant^?1 (T₁₁) significantly enhanced the number of fruits plant^?1 (327.88), yield plant^?1 (29.03 kg) and yield ha^?1 (4.52 t). However, the soil microbial count of fungi (8.89 cfu g^?1 soil), bacteria (11.19 cfu g^?1 soil) and actinomycetes (5.60 cfu g^?1 soil) at fruit harvest was higher under the 2/3 of RDF +10 kg vermicompost + 250 g Azospirillum + 250 g Azotobacter plant^?1 (T₁₅). The leaf nitrogen content (N, 2.03%) was higher in T_15, while phosphorus (P, 0.28%) and potassium (K, 1.80%) content were higher in T₁₁. It is evident that treatment T₁₁ increased fruit yield by 32% in Sapota cv. Kalipatti compared to control. Therefore, combined application of nutrient sources proved not only beneficial for enhancing fruit yield of sapota but also sustaining soil health in Chambal region of south-eastern Rajasthan.     

四川省番茄养分管理技术现状与评价

在农户抽样调查数据的基础上,分析了2008年四川省番茄养分管理现状。调查结果表明,四川省番茄养分管理存在许多不合理之处,氮素施用普遍偏高,全省平均用量269.1kghm-2,有67.3%的农户氮素施用过量,仅有25.5%的农户施氮合理。磷素、钾素投入量严重不足,全省磷、钾养分平均投入量分别为164.5kghm-2和123.3kghm-2,49.1%的农户磷素施用偏低,65.5%的农户钾素施用不足。肥料品种结构、施肥方法及施肥量确定依据不合理。52.4%～80.0%的农户采用肥料穴施,8.5%～74.4%的农户仍按照习惯确定施肥量。四川省今后提高养分效率、减少化肥污染需要重点解决这些问题。     

Method for Preparation of Nutrient-depleted Soil for Determination of Plant Nutrient Requirements

ABSTRACT

Research for nutrient optimization and crop nutrient use efficiency requires precise control on soil nutrient status. While nutrient-depleted soils are preferable to artificial soils or hydroponics, reliable and affordable methods for nutrient removal are lacking. We report the systematic standardization and validation of a simple method to wash soil with purified deionized water for the removal of nutrients such as nitrogen (N), phosphorus (P), potassium (K), calcium (Ca) and organic carbon. Sandy soil was washed with RO water (1:1, w/v) followed by several washes with Type 1 ultrapure water (2:1, w/v) and tested after each wash for the removal of organic carbon, N, P, K, and Ca. After seven washes, total dissolved solids (TDS) were reduced to 5 ppm, conductivity to 10 µS, organic carbon content was reduced by 78%, while N by 19.5%, P by 30%, K by 48% and Ca by 29%. Two genotypes of rice were grown for full life cycle under normal and low N fertilizer (urea) levels to demonstrate that soil depleted with nutrients by our method supports normal plant growth in the greenhouse and allows experiments impossible under field conditions. Precise control on the nutrient status of the soil by our method also helped demonstrate yield differences between genotypes and N regimes and also that higher grain yields can be obtained with low nitrogen (N) input. Thus, our method facilitates better design of experiments for precise determination of nutrient requirements for crop growth and nutrient use efficiency.     

中国设施栽培系统中的养分管理

设施栽培养分管理是设施农业系统的重要组成部分,根据近年来我国设施农业在养分管理方面的研究进展,从设施栽培养分投入和土壤养分累积两个方面阐述了我国设施栽培养分管理现状,指出了由于不合理养分管理导致的设施栽培土壤盐分大量积累、营养元素间比例失调、设施蔬菜品质下降以及造成的环境污染等问题,并针对上述问题提出了加强设施栽培养分管理的一些具体对策及措施。     

Evaluating a Rapid Method to Determine Faecal Burden on Pasture from Grazing Cattle

Grazing livestock excrete large volumes of faecal material on pasture. Understanding the magnitude of this faecal burden is important for attributing sources of agricultural pollutants to different spatial and temporal scales. This field-based study evaluated the utility and transferability of a rapid approach often used in plant ecology (the line intercept method (LIM)) for estimating faecal burden from grazing cattle on pasture. Results from the LIM were of equivalent magnitude, with no significant difference observed, to those derived from more time-consuming sampling of faecal material from pasture using a quadrat-style methodology (herein termed burden sampling). However, the variability in estimates using the LIM was much larger (839?C7,079?kg fresh weight faeces over the 50,000?m² field) compared with estimates provided by the burden sampling of pasture at 0.2?% area sampled (1,616?C3,979?kg/50,000?m²), 0.4?% area sampled (1,753?C2,723?kg/50,000?m²) and 0.8?% area sampled (1,212?C2,344?kg/50,000?m²). The LIM offers a rapid and cost-effective alternative to time-consuming sampling campaigns of faecal burden on pasture and provides estimations that are preferable to back-of-the-envelope calculations based on the over-simplification of livestock excretion rates.     

长期定位施肥对旱作塿土小麦产量、养分效率及养分平衡的影响

本文以20年塿土冬小麦-夏休闲轮作体系长期肥料定位试验为平台,探讨小麦产量、肥料利用效率及养分平衡对长期不同施肥模式的响应。试验包括7种施肥模式:不施肥(CK)、单施氮肥(N)、氮磷(NP)、氮钾(NK)、磷钾(PK)、氮磷钾(NPK)、有机肥与氮磷钾化肥配施(MNPK)。结果表明,同时施入氮肥和磷肥处理的小麦产量上升趋势显著,年均增产幅度为219~265 kg hm-2。施氮肥处理土壤氮素盈余,施磷肥处理土壤磷素盈余。以N和NK氮素盈余最多,年均盈余分别为88 kg hm-2和66 kg hm-2,MNPK土壤磷素盈余达到107 kg hm-2。同时施入氮磷肥处理(NP、NPK)显著提高了氮(磷)肥的累积表观利用率、农学效率和偏生产力,MNPK仅显著提高了氮肥的累积表观利用率、农学效率和偏生产力。除了PK和MNPK外的其它处理,土壤钾素均呈亏缺状态,以NP亏缺最严重,达到103 kg hm-2a-1。施钾肥对钾肥累积表观利用率、钾肥农学效率以及钾肥偏生产力均没有明显影响。20年后,土壤有机质、全氮、速效磷和速效钾含量均以MNPK最高。旱作塿土合理的施肥措施为氮磷配合或有机肥配合氮肥。     

关于开发建设项目水土保持方案编制和实施中有关问题的思考

当前在开发建设项目水土保持方案的编制和实施过程中 ,存在着内容程式化、涉水工程未经水行政主管部门审批即予实施、水土流失预测不科学、水保补偿费不列入报告、方案编制受行政干预、批准后的方案得不到很好贯彻实施等问题。水土保持主管部门应加快技术规范的制定、做好部门间的协调沟通、加强监督检查、加大执法力度等 ,进一步提高水土保持方案编制的质量和实施效果。     

Performance of an Optimized Nutrient Management Approach for Tomato in Central Sri Lanka

A systematic approach of fertilizer recommendation for tomato was evaluated in central Sri Lanka. An optimum (OPT) treatment was formulated based on soil analysis for available nutrients and nutrient-fixation capacities and tested with sorghum (Sorghum vulgaris L.) in a greenhouse and with tomato (Lycopersicon eculentum L.) in the field for four seasons. Soil analysis revealed deficient levels of nitrogen (N), phosphorus (P), potassium (K), sulfur (S), boron (B), and zinc (Zn) with high fixing capacities for P, K, S, and B. Greenhouse survey confirmed nutrient deficiencies except for Zn. A field study with 17 treatments including OPT showed significant main effects and interaction of fertilizer treatment and season for tomato yields and profit. The OPT providing 220 kg N, 160 kg P, 250 kg K, 50 kg S, and 1 kg B per ha often gave greater yields and profits than treatments with lower nutrient rates, but treatment providing N, P, and K at 150% of optimum was superior.     

A Rapid Microassay for Determination of Peroxidase in Wheat and Flour

A rapid sensitive microplate assay for the determination of peroxidase activity in wheat, flour, or individual wheat kernels has been developed using a commercially prepared 2,2′‐azinobis(3‐ethylbenzothiazoline‐6‐sulfonic acid) diammonium salt (ABTS) solution. The assay derives a six‐point calibration curve based on commercially available horseradish peroxidase (r² > 0.990), while simultaneously analyzing eight extracts in triplicate. The coefficients of variation (CV) of triplicate assays of a single extract from any of the three sources investigated were generally <2.0%. Multiple extracts (n = 5) of either whole meal or flour yielded assays with an average CV < 5.0%. Preparation of the calibration standards with commercially available peroxidase stabilizing buffer allowed the standards to be used for five days without any deterioration in the assay's reproducibility. This assay is ideally suited for high‐throughput operations such as millstream analysis or plant breeder screening evaluations.     

Nutrient Management for Sustaining Productivity of Sunflower-Based Cropping Sequence in Indian Semiarid Regions

A comprehensive long-term study (2006–2010) was undertaken to develop a balanced and integrated nutrient supply system for sunflower-based cropping sequence considering the efficient utilization of residual and cumulative soil nutrient balance along with added fertilizers by the crops grown in rotation. The fertilizer application was done in potato and sunflower while greengram was raised as such on their residual effect. Significant response in yield was observed with 150% of the recommended nitrogen, phosphorus and potassium (NPK) or inclusion of farmyard manure (FYM) with the recommended NPK in the cropping sequence indicating 6.2–7.0% gain in system productivity over the existing recommendations. Each additional unit of P and K nutrition prompted system productivity by 18.9 and 11.0 kg kg^?1 of applied nutrient, respectively. Apparent yield decline was observed in K and PK omission plots to the extent of 15.8 and 27.4% in potato, 10.5 and 23.9% in sunflower and 4.2 and 8.3% in greengram, respectively, compared to the recommended fertilization. The superiority of the FYM along with the recommended NPK (potato/sunflower) was evident on the overall profitability and sustainability of the system, highlighted by the significantly higher productivity (7.16 t SFEY ha^?1), sustainability yield index (SYI; 0.76), production efficiency (PE; 27.85 kg SFEY ha^?1 day^?1) and net returns (2520 USD ha^?1) with a B:C ratio of 2.91. Apparent change in potassium permanganate (KMnO₄)-N was negative in all the treatments while N and P balance was positive with 150% NPK fertilization. Nutrient uptake exceeded the replenishment with 100% NPK application and maintained net negative soil nutrient stock for all the primary nutrients, indicating the need for revalidation of the existing recommendations in the system perspective. Conspicuous improvement in residual soil fertility in terms of maximum buildup of soil organic carbon (14%) and enhancement in soil KMnO₄-N (4.2%), Olsen-P (19.4%), ammonium acetate (NH4OAc)-K (5.8%) and dehydrogenase enzyme activity (44.4%) was observed in FYM-treated plots over the initial values. The study suggested that the inclusion of legumes and FYM application with the recommended NPK in potato-sunflower cropping sequence will sustain the system’s productivity through the efficient use of nutrients, enhanced microbial activity and improved soil health while combating escalating prices of fertilizers as well as environmental issues in the Indo-Gangetic plains of India and similar environments.     

Nutrient Management Practices Used in Potato Production In Idaho

Sound nutrient-management practices are an essential component of modern intensive potato (Solanum tuberosum) production systems. Economic and environmental issues are requiring Idaho potato producers to use management practices that are effective and efficient to remain competitive in the market. Identical potato production management surveys were conducted in 1997 and again in 2006–2007 to determine current nutrient management practices used by Idaho potato growers. This Dillman mail-based survey collected data that were used to determine current nutrient-management strategies and changes that have occurred over the past 10 years. In 2006–2007, more than 77% of growers used preplant soil tests for determining nitrogen (N) application needs. More than 96% of potato growers relied on petiole analysis of potato plant tissue for N management during the growing season. Changes have occurred in only 7 of 28 nutrient-management categories evaluated in the past 10 years, indicating maturity rather than evolution in nutrient management strategies for potatoes. Over the past 10 years, application rates of N have decreased, while potassium (K) rates have increased. There has been a decrease in the number of growers who plant legumes in crop rotation as a source of N. The use of nitrification inhibitors, precision fertilizer management, and application of manure to potato fields has increased in the past 10 years. The overall lack of changes in nutrient management in the past 10 years may indicate that nutrient-management strategies for potatoes in Idaho are mature and successful.