关于我区部分地区耕作土壤肥力情况及改良措施的探讨

内蒙古地区土地资源丰富，各地土壤肥力差别较大，本文对我区六地区耕作土壤进行了土壤肥力调查，通过分析了７７ 个土壤样品的ｐＨ 值、有机质、有效氮、速效磷、速效钾，比较全面地了解了六个地区耕作土壤肥力情况，并提出了一些土壤改良的意见。     

施肥对土壤环境中砷污染的影响

通过盆栽试验研究了不同施肥处理与外源砷污染对土壤肥力及砷形态的影响。结果表明,在同一砷浓度处理条件下,与空白处理相比,有机肥+化肥处理土壤有效磷和速效钾含量增加量最多,分别增加了1.29倍~26.75倍、0.44倍~2.14倍,对土壤全氮和有机质的影响不大,同一砷浓度下土壤中各种砷的形态差异不大(P0.05);在同一施肥处理下,随着外源砷浓度的增加,土壤有效磷呈显著增加的趋势,土壤全氮和有机质的含量差异不显著;土壤总砷含量呈现显著增加的趋势,外源砷质量分数从0mg/kg~100mg/kg,土壤总砷含量平均显著增加了81.8mg/kg,土壤可交换态砷和碳酸盐结合态砷在外源砷加入量为10mg/kg时含量最低。     

蚯蚓资源治理农业污染研究

蚯蚓与微生物的共同作用,通过提高土壤中速效态氮、磷、钾等养分的含量,可以显著改善土壤肥力,是发展绿色农业、处理固体废弃物的一种优良物种;通过蚯蚓对土壤中重金属的富集作用,也可以有效去除污染土壤、有害固体废物中的重金属物质,同时可通过蚯蚓体内聚集重金属的多少以及产生的反应,作为评测土壤重金属污染的标志。     

风化煤腐植酸对土壤理化性状的影响

以潮土和棕壤土为研究对象,通过添加不同量未活化和活化的风化煤腐植酸,对比研究了2种腐植酸对土壤肥力和理化性状的影响。试验结果表明：单施未活化的风化煤腐植酸和活化的风化煤腐植酸对土壤中全氮含量无明显效果,但可以活化和释放土壤中难溶性磷、矿物态钾、缓效性钾,使其转化成速效磷和速效钾;施用3个月后,2种土壤中速效磷、速效钾、阳离子交换量、水稳性团聚体均有不同程度的增加。其中,碱活化的风化煤腐植酸对土壤理化性状具有良好的影响,可使2种土壤中的速效磷含量、速效钾含量、阳离子交换量、水稳性团聚体数量分别增加24.80-130.87 mg/kg、43.01-113.19 mg/kg、8.87-9.49 cmol/kg、8.01%-18.84%。     

长期施肥对作物氮磷利用及土壤速效氮磷供应能力的影响

通过北京昌平"国家褐潮土土壤肥力和肥料效益监测基地"的长期定位试验(1991~2004年),研究了褐潮土务件下长期施肥对作物氮磷吸收利用及土壤速效氮磷供应能力的影响.主要结论是:无论是作物总养分吸收量还是养分表观利用率,氮磷钾配合施用均高于单一施氮或氮磷钾两两配合处理;耕层土壤碱解N含量氮磷钾配施有机肥或秸秆处理优于单施化肥;氮磷钾配施有机肥土壤速效磷含量比不施肥增加11倍,而磷钾比对照增加5倍;氮磷、或氮磷钾配施秸秆、或氮磷钾配合分别比对照增加3倍左右.     

卤水制制碱与离子膜法工艺结合的几个问题

研究结果表明，土壤肥力、结球初期大白菜中、上部莲座叶内矿质元素含量与大白菜产量和净菜率呈正相关关系，特别是土壤中有机质、速效氮含量与产量的关系最为密切，相关系数分别为ｒ＝０．８５１２，ｒ＝０．９５３５，叶内的氮、磷、钾、钙、铜、铁、锰也与大白菜产量呈显著相关。     

香蕉专用肥的肥效试验

香蕉是云南省低海拔热带河谷地区的主要经济作物。个旧市化肥厂农化中心根据香蕉生长发育特点和需肥规律 ,结合当地土壤养分情况 ,提供 10 5 2 0和 8816两种硫基型香蕉专用肥 ,与个旧市农技推广中心合作进行肥效试验 ,现将试验结果介绍如下。1　供试土壤土壤肥力中上等 ,海拔 3 5 0 m,缓坡 ,土壤为砂燥红土。养分情况 :p H6.8,有机质 11.88g/ kg土 ,全氮 1.87g/ kg土 ,碱解氮 194m g/kg土 ,全磷 0 .2 76g/ kg土 ,速效磷 2 .74m g/ kg土 ,全钾 13 .5 7g/ kg土 ,速效钾 2 95 m g/ kg土 ,土壤含水 40 .5 8g/ kg土 。2　供试材料香蕉品种为“威…     

腐植酸肥料对连作花生土壤性质和土壤微生物多样性的改善

正在华北平原进行了连续3年的花生种植试验,研究了腐植酸对连作花生土壤理化性质、微生物多样性和酶活性的影响。除氮、磷、钾输入量相等外,设置无机肥配施腐植酸处理。与对照相比,腐植酸提高了连作花生的产量和品质。为了阐明腐植酸对土壤质量的影响机理,本研究对各种土壤质量指标进行了评价和比较。研究发现:腐植酸提高了土壤养分含量,包括土壤全氮、全磷、全钾、速效氮、速效磷、速效钾和有机质含量,在第3年中效果最好;同时,腐植酸处理后土壤脲酶、蔗糖酶和     

腐植酸钾对黄冠梨土壤肥力的影响

研究腐植酸钾对黄冠梨土壤中腐植质、氮、磷、钾含量的影响。结果表明：腐植酸钾显著提高土壤腐植质含量和速效氮、磷、钾含量,对土壤中全量养分影响不大。腐植酸钾具有改良土壤,增加肥效作用。     

黄腐酸对植烟土壤改良及烟叶品质的影响研究

以“云烟97”为研究对象,通过大田试验,于2014年研究了不同黄腐酸施用量对植烟土壤改良及烟叶品质的影响。试验结果表明：施用黄腐酸提高了土壤速效磷、速效钾、碱解氮、有机质、土壤微生物生物量碳、土壤微生物生物量氮含量,并促进土壤中三大菌落的繁殖,但施用黄腐酸对土壤微生物多样性促进效果不明显;黄腐酸促进了烟株根系发育,提高了烟株根系体积,干、鲜重;     

有机肥料中有机质检测影响因素探讨

有机肥料在农作物生长过程中起着非常重要的作用。通过合理施加有机肥料,可以有效提升土壤肥力,提高农作物的产量和品质。土壤中有机质的含量是判断土壤肥力的重要依据。所以,在农业种植中要特别重视测定有机肥料中有机质的含量。作为检测有机质的一线人员,在检测过程中发现采用不同的标准、方法都会对检测结果产生影响。主要分析了有机肥料中有机质的检测方法以及应该注意的事项。     

Soil fertility status and nutrient input–output flows of specialised organic cropping systems: a review

The management of specialised organic crops for vegetable and fruit production require the use of imported fertilizers. A wide range of fertilizers is currently available to organic farmers. These include bulky organic materials with a relatively low nutrient concentration commonly used as base dressing (e.g. composts, solid animal manures) and complementary commercial organic fertilizers with relatively high nutrient concentrations to adjust nutrient supply to crop requirements (e.g. feather meal, hoof and horn meal, vinasse, meat and bone meal, etc.). Nutrient imbalances are a major threat affecting the long term sustainability of horticultural and fruit cultivation systems. Major reasons for these imbalances are the biased element composition of base as well as complementary fertilizers in relation to the nutrient offtakes via harvested products. Gaseous nitrogen losses during manure management and gaseous as well as leaching nitrogen losses after application are major reasons for such nutrient imbalances, as they lead to a relative increase in the concentration of other elements. Conceptual weaknesses in the fertilizer approach in organic farming exist, namely the preferred application of slow release nitrogen fertilizers often rich in phosphorus. This review suggests that the current soil fertility approaches based on application of solid fertilizers and simultaneously a low rate of N inputs via N₂ fixation do not foster balanced nutrient levels. The key challenge is to design cropping systems with a higher share of N inputs via biological N₂ fixation, and to find fertilizers with a nutrient stoichiometry better suited to match the overall specific offtakes of fertilized crops.     

Composting of Disposal Organic Wastes: Resource Recovery for Agricultural Sustainability

One of the major problems of agricultural soils in the tropical regions of the Pacific is the low organic matter content. Because of the hot and humid environment, the soil organic matter (SOM) is minimal due to rapid decomposition. Composted organic material is being applied on agricultural fields as an amendment to provide nutrients and enhance the organic matter content for improving the physical and chemical properties of the cultivated soils. In addition land application of composted material as a fertilizer source effectively disposes of wastes that otherwise are buried in landfills. In our soil program at the University of Guam, we are evaluating the use of organic material as an alternative to synthetic fertilizers. Its goal is to develop management strategies and use available resources for improving crop production while conserving resources and preserving environmental quality. Our case study project is designed to improve soil fertility status by using composted organic wastes and assessing how the nitrogen and other essential nutrients contribute to long-term soil fertility and crop productivity without application of synthetic fertilizers. In our pilot project, compost is produced from wood chips, grinded typhoon debris mixed with animal manure, fish feed, shredded paper and other organic wastes. Mature compost is then applied on the field at the rates of 0, 5, 10 and 20 t/ha as a soil amendment on the eroded cobbly soils of southern Guam. Corn is planted and monitored for growth performance and yield. The effect of land application of composted material on the SOM content and overall soil quality indices are being evaluated in this pilot study.     

Appropriate technologies to replenish soil fertility in southern Africa

In southern Africa, soil nutrient reserves are being depleted because of continued nutrient mining without adequate replenishment. The consequent downward spiral of soil fertility has led to a corresponding decline in crop yields, food insecurity, food aid and environmental degradation. The central issue for improving agricultural productivity in southern Africa is how to build up and maintain soil fertility despite the low incomes of smallholder farmers and the increasing land and labour constraints they face. Under this review five main options namely: inorganic fertilizers, grain legumes, animal manures, integrated nutrient management and agroforestry options appropriate to smallholder farmers are presented. Issues addressed in the use of inorganic fertilizers are reduction in fertilizer costs, timely availability and use efficiency. Legumes can be used to diversify farm system productivity but this requires P and lime application to support better legume growth and biological nitrogen fixation (BNF) as well as development of markets for various legume products. Manure availability and quality are central issues in increasing smallholder farm productivity and increasing its efficiency through proper handling and application methods. Integrated nutrient management of soil fertility by combined application of both inputs will increase use efficiency of inputs and reduce costs and increase profitability; but the challenge is often how to raise adequate amounts of either inorganic or organic inputs. Issues such as quality of inputs, nutrient balancing, labour to collect and transport organic inputs and their management need to be optimized. These are the challenges of adoption as are the scaling up of these options to millions of small-scale farmers.     

Quantification of soil patterns and field soil fertility using spectral reflection and digital processing of aerial photographs

Direct spectral reflectance measurements of soils and multi-emulsion analysis of aerial photographs were carried out to document possible uses of these techniques for soil and fertility management in agricultural fields where the within field soil variability is high. A spectrometer with four broadband filters and a multi-emulsion film scanner were used to quantify the soil conditions in an agricultural field where the soil pattern was made up of three distinctly different soil types. The spectral data from soil samples and the data from the multi-emulsion analysis of the aerial imagery were then compared and related to the soil chemistry. The spatial pattern of the soils in the test field was quantified by cluster analysis using the brightness values obtained from the multi-emulsion analysis of the aerial photo. Percent organic carbon, water content, and color value were the most sensitive variables to be related to the remote sensing data. Using these techniques in conjunction with conventional soil analysis facilitated the determination of fertilizer requirements in the field. Given the field soil pattern, optimum fertility management can be achieved by using differential rates of fertilizers for two of the three soils identified via remote sensing. The results suggest that for the field used in this study the remote sensing techniques can facilitate the application of variable rates of fertilizers.     

Soil organic matter dynamics as affected by long-term use of organic and inorganic fertilizers under maize–wheat cropping system

Understanding the effects of long-term use of fertilizers on soil carbon and nitrogen pools and their activities is essential for sustaining soil productivity. Our objectives were to quantify long-term changes in soil organic carbon (SOC), soil microbial biomass carbon (SMBC), soil microbial biomass nitrogen (SMBN) and mineralizable C in maize–wheat cropping sequence in fertilized and unfertilized plots (control, N, NP, NPK, and NPK + FYM). Continuous application of fertilizers increased SOC over its initial content. Active fractions of SOC, i.e., water-soluble carbon, hydrolysable carbohydrates, SMBC, SMBN and dehydrogenase activity, improved significantly with an application of NPK and NPK + FYM. A general increase in carbon mineralization with time period was observed throughout the experiment and was maximum in 100% NPK + FYM treated plots. The estimated annual C input value in NPK + FYM treatment was 1.05 MgC ha⁻¹ year⁻¹. The overall net change in organic carbon was maximum in treatment receiving FYM along with inorganic fertilizers. Therefore, these results suggest that the integrated use of NPK and FYM is an important nutrient management option for sustaining maize–wheat cropping system.     

Role of manures and crop residue in alleviating soil fertility constraints to crop production: With special reference to the Sahelian and Sudanian zones of West Africa

In the West African semi-arid tropics (WASAT), continuous cultivation leads to drastically reduced levels of soil organic matter. Such reductions in the level of soil organic matter have resulted in decreased soil productivity. The addition of organic materials either in the form of manures or crop residue has beneficial effects on the soils' chemical and physical properties. For many of the countries in this region, the amounts of nutrients in crops and crop residue are often several orders of magnitude higher than the quantity of the same nutrients applied as fertilizers. The return of the crop residue for soil fertility improvement cannot be overstressed. It is essential that more information on the rates of organic matter decomposition as well as the many reactions between products of organic matter decomposition and the soil under WASAT conditions be made available.     

Management of organic matter in the tropics: translating theory into practice

Inputs of organic materials play a central role in the productivity of many tropical farming systems by providing nutrients through decomposition and substrate for synthesis of soil organic matter (SOM). The organic inputs in many tropical farming systems such as crop residues, manures, and natural fallows are currently of low quality and insufficient quantity to maintain soil fertility hence there is need to find alternative or supplementary sources of nutrients. Knowledge gained over the past decade on the role of organic resource quality in influencing soil nutrient availability patterns (Synchrony Principle) and SOM maintenance (SOM Principle) provides a strong scientific basis on which to develop management tools. This scientific information must be linked with farmer knowledge and circumstances to provide a realistic approach to soil fertility and SOM management in the tropics. A decision tree has been developed for testing hypotheses about the resource quality parameters that affect nitrogen release patterns and rates. The decision tree is linked to an Organic Resource Database (ORD) with detailed information on the resource quality of agroforestry trees and leguminous cover crops providing a systematic means of selecting organic resources for soil fertility management. The decision tree has also been translated into a practical field guide for use with farmers in evaluating organic materials. The longer-term effects of organic inputs on SOM might also be addressed through the decision tree and database. It is generally believed that materials good for short-term soil fertility will not build or maintain SOM; if true then it is difficult to imagine practical means of maintaining SOM in the African context where short-term fertility issues will take precedence over longer-term maintenance of SOM. This revised version was published online in June 2006 with corrections to the Cover Date.     

Profitability of agro-forestry based soil fertility management technologies: the case of small holder food production in Western Kenya

Persistent food insecurity accompanied by low and declining farm household incomes are a common feature of many small holder maize and bean producers in western Kenya. This has been largely attributed to soil nutrient depletion, among other factors. One way of addressing soil fertility problems in many maize-based cropping systems is the use of agro-forestry based technologies. We carried out a survey in western Kenya (Vihiga and Siaya districts) aimed at analyzing the financial and social profitability of use of agroforestry based (improved tree fallows) and other soil fertility management technologies among smallholder farmers. The Policy Analysis Matrix (PAM) was used to determine the financial and social profitability of different production systems, which were categorized on the basis of the technology used to address soil fertility. Farm budgets were first prepared and in turn used to construct the PAMs for six production systems namely: maize–bean intercrop without any soil fertility management inputs; maize–bean intercrop with chemical fertilizers only; maize–bean intercrop with a combination of chemical fertilizers and improved fallows; maize–bean intercrop with improved fallows only; maize–bean intercrop with a combination of improved fallows and rock phosphate; and maize–bean intercrop with Farm Yard Manure (FYM) only. Results revealed that use of chemical fertilizers with improved fallows was the most profitable technology and thus the study recommended that farmers be encouraged to intensify the use of chemical fertilizers. To make chemical fertilizers more accessible to farmers, the study also recommended that good linkages be made between farmers and micro credit institutions so that small scale farmers are not actually biased against due to lack of collateral when credit is being advanced to clients.     

发展腐植酸类有机肥提高化肥利用率

论述腐植酸类有机肥、有机无机复合肥对提高化肥利用率和土壤肥力的重要作用。提出利用食品工业废弃物生产氨基酸类有机无机复合肥;利用泥炭、褐煤、风化煤、蒿秆、木屑等生产腐植酸类有机无机复合肥;发展精制生物有机肥;而功能型生物有机肥将开辟有机肥料新领域。