Soil Organic Matter Improvement Research Articles

Effects of Application of Different Organic Materials on Phosphorus Accumulation and Transformation in Vegetable Fields

Presently, the improvement of soil organic matter is the basis to ensure food security, but the accumulation and transformation characteristics of soil phosphorus (P) as affected by organic matter remain unclear. The accumulation, transformation, and migration characteristics of soil P in different soil layers of vegetable fields were researched under the application of organic materials. Six treatments were set up in the experiment:control (no fertilization), traditional fertilizer application by farmers, biochar, chicken manure, food waste, and straw application. Available phosphorus (Olsen-P), water-soluble phosphorus (CaCl2-P) content, soil phosphorus forms, soil organic matter (SOM), and pH were determined during the pepper harvest period. In the 0-5 cm and 5-10 cm soil layers, the available phosphorus content of traditional fertilization of farmers was higher, and the available phosphorus content of the four organic materials was in the order of straw > biochar > chicken manure > food waste. Compared to that with food waste, the straw and biochar treatments increased soil available phosphorus by 59.6%-67.3% and 29.1%-36.9%, respectively. The straw treatment could easily enhance the soil labile P pool, and soil labile P in the 0-5 cm soil layer increased by 47.3% and 35.1% compared with that under the chicken manure and food waste treatments, respectively. With the increase in soil depth, the proportion of available phosphorus in the chicken manure treatment decreased the least, and available phosphorus of the 20-30 cm soil layer accounted for 55.9% of the topsoil layer but only accounted for 16.0%-34.0% under treatment with the other three materials. Compared with that under the traditional fertilization of farmers, the pH significantly increased by 0.18-0.36 units after the application of organic fertilizer, and the pH of the chicken manure and food waste treatments was significantly higher than that of biochar and straw (P < 0.05). SOM content under the biochar treatment significantly increased by 7.7%-17.6% compared to that under the other three organic materials. Among the four organic materials, the straw treatment boosted the labile P pool the most, which was conducive to the rapid increase in plant-available P. Phosphorus was most likely to migrate downward under the chicken manure treatment. In the field management based on soil fertility enhancement, the application of biochar could not only improve soil pH and SOM but also avoid excessive accumulation of phosphorus in the surface layer, which decreases environmental risks.

Review of the Responses of Various Soil Amendments in Sandy Soils

The primary constraints with sandy soils are low soil organic matter content, poor nutrient availability, heavy losses of applied nutrients and lower water holding capacity. Improving the productivity of sandy soils, particularly in developing countries, could be a viable solution to food insecurity and poverty. Large extent of sandy soil is one of the major constraints for crop production in the Eastern Province of Sri Lanka. Meanwhile, various soil amendments can be applied to improve the performances of cropping systems in sandy soils. Nevertheless, a comprehensive knowledge on which soil amendment would work better across different scales is not well known. To address this knowledge gap, this review was conducted using published literature. Systematic review approach was adopted, and the data were extracted from 65 highly relevant papers. The data were analyzed to calculate the percentage changes on crop yields, soil organic matter and soil carbon, in response to the applications of different soil amendments. The review highlighted the potential of several soil amendments to improve the crop performances in sandy soils. Interestingly, rice straw biochar and the municipal solid waste compost have greatly increased crop yields especially in rice at the rate of 0.9% w/w and 3% w/w in soil weight basis, respectively. Highest improvement in soil organic matter and soil carbon was observed under the applications of compost and spent grain, respectively. Therefore, rice straw biochar and compost could be evaluated to improve the productivity of sandy soils, especially in the Eastern region of Sri Lanka. Although the spent grain was promising, the availability for large scale applications may be limited in Sri Lanka. Testing of these soil amendments would require long-term experiments incorporating different crops and cropping systems. 
 Keywords: Compost, Biochar, Sandy soil, Soil amendments

Alleviation of Cd stress in maize by compost mixed biochar

Cadmium (Cd) is a heavy metal that neutrally occurs in soil. It is carcinogenic in humans and caused a significant decline in the plant’s growth when up has taken beyond the threshold limit. The fertilizers, manure, sewage sludge, and aerial deposition are the main source of cadmium contamination in soil. Furthermore, poor soil organic matter is also one of the allied factors which facilitate the development of Cd toxicity in soil. The decomposition resistance nature of biochar makes it an effective amendment for cadmium remediation. Through crop production, Cd enters the food system. Individual studies on biochar and compost are found in the literature but the combined effect of biochar and compost are rarely documented especially in maize crops. The current pot study was conducted in Pesticide Quality Control Laboratory, Multan, Pakistan. However, the current study was novel and conducted by using compost mixed biochar (CB) against Cd toxicity in maize. Four application rates of CB i.e., 0, 0.50, 0.75 and 1.00% (1.00CB) were applied under 3 levels of Cd i.e., 0 (0Cd), 2.5 (2.5Cd) and 5 mg Cd kg−1 soil (5.0Cd). Overall, results indicated that 1.00%CB remained significantly best at higher 5.0Cd for improvement in soil organic matter, plant height, root length, number of leaves, leaves fresh and dry weight, plant fresh and dry weight, chlorophyll a, b, total and carotenoids. A significant decrease in soil pHs, leaves anthocyanin and lycopene also validated the efficacious functioning of 1.00%CB over control in 2.5 and 5.0Cd. In conclusion, the use of 1.00%CB is a better approach to decrease Cd harmful effects to improve gas exchange attributes, growth and chlorophyll contents in maize. Long-term research is required on co-composted biochar toward mitigation of cadmium toxicity under different geographical locations.

Resource conservation technology for sustainable productivity of intensive rice-based cropping pattern in Bangladesh

Exhaustive conventional tillage and removing residues of previous crops in the rice-based cropping system are labor intensive, costly, soil destructive and non-ecofriendly. In recent years, increased concerns for healthier food production and environmental quality, and increased emphasis on sustaining the productive capacity of soils, have raised concern in the maintenance and improvement of soil organic matter through appropriate land use and management practices. Strip tillage with the application of herbicides and crop residue mulching are being developed to overcome this challenge. A two-year experiment of the summer rice-mustard-winter rice (R-M-R) system was conducted at the farmers’ field in the northern Bangladesh during 2014-2016. Summer rice (BRRI hybrid dhan6), mustard (BARI Mustard 14) and winter rice (BRRI dhan28) were grown under, T1: Conventional tillage (CT) + three hand weeding (Control) and T2: Pre-plant herbicide (PRE) + strip tillage (ST) + pre-emergence herbicide (PE) + post-emergence herbicide (PO) with two levels of crop residue mulching, M0: no-mulch and M50: 50% standing mulch. The CT consisted of two primary tillage operations by a two-wheel tractor, and ST had done by a Versatile Multi-crop Planter in a single-pass process. The PRE (glyphosate) and PE (pendimethalin) in all crops and the PO (ethoxysulfuron-ethyl in rice and isoproturon in mustard) were applied at recommended dose and time. The combination of applied PRE, ST, followed by PE and PO herbicide and the retention of 50% mulch fetched the highest yield and economic returns of individual crop and the productivity of the summer rice-mustard-winter rice system.

Maize and sunflower yields and soil changes after five years of organic fertilization in the semi-arid region of Paraiba, Brazil

Effects of annual organic fertilization on maize and sunflower yields and on physical and chemical characteristics of a Fluvisol were evaluated in the semiarid area of Paraiba state, from 2007 to 2011. The experiment was a block design in a 4 × 2 factorial arrangement, corresponding to one control and three fertilizer treatments (cattle manure and Gliricidia sepium and Croton sonderianus prunings) and two application procedures (soil surface or incorporated in the 0–10 cm layer), with four replications. Maize was grown in the first 3 years and then sunflower was grown for 2 years. Grain and straw yields increased with fertilization, especially in the years of good rains (maize, 0–61%, reaching 3.4 Mg ha−1 of grain; sunflower, 48–112%, reaching 1.4 Mg ha−1 of achenes), differing only slightly between fertilizer types and form of application. All fertilizers incorporated for 5 years reduced water infiltration time (20–50%), but only manure and G. sepium reduced soil bulk density (about 10%) and increased soil porosity (7–10%). Manure increased soil pH (0.7–1.0 units). Surface application of manure and C. sonderianus increased soil organic matter (28 and 72%) and phosphorus concentrations (about 70%). We suggest that, in sites with soil physical problems (slow water infiltration, high soil compaction, and low porosity), organic fertilizers may lead to better responses if incorporated into the soil. If there is a need for greater improvement of soil organic matter, nutrients and water conservation, surface applied organic manure and C. sonderianus may be a better management practice.

Biofertilizer Impacts on Cassava (Manihot Esculenta Crantz) Cultivation: Improved Soil Health and Quality, Igbariam, Nigeria

Cassava crop cultivation microbiome impacts by microbial biofertilizer is an integral function of the agro-ecology, its evolution (yield, soil health and quality) for sustainable agriculture. Increased yield and nutrient bioavailability powered by co-inoculation of microbial consortia adaptability to the soil ecology. Biofertilizer solves the traceability problem of chemical farm inputs, suitability and nutrient use efficiency as an integral function of the rhizosphere microbiome ‘tailor’ integrated soil fertility management that improves micronutrient and macronutrient via plant microbe interactions for soil health quality and crop degradation management.Mycorrhizal spp mutualistic symbiosis with plant roots satisfies the crop nutrients requirements. Aspergillus spp, Bacillus spp and Clostridium spp in the biofertilizer enhances potassium solubilization, a major challenge in cassava crop nutrition development of the biomass and mineralization. Soil organic matter improvement as a function of biofertilizer application help management of carbon sequestration and climate vulnerabilities.

The metabolic and genetic diversity of soil bacterial communities depends on the soil management system and C/N dynamics: The case of sustainable and conventional olive groves

Under Mediterranean type climates, a sustainable soil management aimed at increasing soil organic carbon and microbiological diversity is of key importance. The aim of this study was to characterize and compare soils from a mature Mediterranean olive (Olea europaea L.) orchard subjected to two different soil management systems (sustainable, Smng, and conventional, Cmng) for 18 years. Composite soil samples were analyzed qualitatively (pedological determinations) and quantitatively (soil C, N and pH). Bacterial metabolic activity and diversity were evaluated spectrophometrically by the Biolog® assay, while 16S-based metagenomics analysis was used to analyse the abundance of N-cycling bacteria. From the general analysis of the data obtained by the study of soil profiles and litter, C and N dynamics, and the genetic and functional diversity of soil bacteria, it emerged that the Smng system caused an improvement in soil organic matter in the topsoil layers, compared to the Cmng system, with consequent increases in the abundance of soil N-cycling bacteria but without affecting the indices related to total bacterial metabolic activity and diversity. The results obtained could promote the development of new approaches for optimizing soil carbon cycling, managing nutrient transport, and sustaining and improving olive yield and quality.

Push-Pull Farming System Controls Fall Armyworm: Lessons from Africa

Fall armyworm (FAW) Spodoptera frugiperda invaded Africa, with the first detections being reported in Central and Western Africa in early 2016, and now affects at least 40 countries in Africa, causing up to total crop loss amounting to over $6.2 billion p.a. FAW is an invasive polyphagous pest that causes damage to economically important crops and has recently been reported in the Indian sub-continent. Effective control of FAW through use of synthetic chemical pesticides and genetically modified crops such as Bt maize faces challenges including improper use, unaffordability by smallholder farmers and development of resistance by the pest. Additionally, dispersal of FAW larvae into the lower maize plant canopy keeps them out of reach of topical insecticide applications. Integrated pest management (IPM) packages like the push-pull technology which eliminate pesticide use, and deploy natural processes are more suitable and cost-effective. Push-pull is a farming system intensification approach that involves attracting insect pests with trap plants (pull) such as Napier grass (Pennisetum purpureum) or Brachiaria grass, while driving them away from the main crop using a repellent intercrop (push), Desmodium spp., commonly known as desmodium, and attracting natural parasitoids and predators to the field. In the rhizosphere, chemicals secreted by desmodium roots inhibit attachment of germinated striga to maize or sorghum roots and abort germination of striga seeds which are rapidly depleted in the soil. Moreover, it improves soil fertility by fixing nitrogen, improving carbon sequestration, organic matter, moisture retention, and soil biota, and prevents further degradation of soil. The climate-adapted push-pull technology significantly reduces plant damage by FAW and is the first IPM management tool for the pest in Africa, and is well suited to agro-ecosystem intensification needs of smallholder mixed farming systems in Africa and beyond. Both the African and the Asian continents provide favourable climatic conditions for sustained reproduction of the FAW, which is expected to result in severe damage to crops; and being a new pest in both continents, it might have few natural enemies. Conventional control methods have limited effectiveness, as explained above. Therefore, an IPM approach that is compatible with mixed cropping farming systems of small and medium scale farmers is necessary. The climate adapted push-pull is the first demonstrated IPM management tool for the FAW in Africa. The technology combines this with other concomitant benefits including control of stemborers and the parasitic striga weeds, improvement of soil health through factors such as nitrogen fixation by desmodium, natural mulching, moisture retention and improvement of soil organic matter and soil biota. The combined benefits, including control of FAW, result in ecologically sustainable higher crop yields, and well suited to agro-ecosystem intensification needs of smallholder mixed farming systems in Africa and beyond.

Soil physical properties and its effects on wheat yield in typical dark loessial soil on Weibei Plateau, China.

Based on the investigations of fertilizer application rates, wheat yield and soil properties (soil compaction) of dark loessial soil on Weibei Plateau in 2015, soil samples from 0-50 cm depth were collected in 61 winter wheat fields. The variability of soil compaction, bulk density, water-stable aggregates and their partial correlations with wheat yield and partial factor productivity were analyzed. The results showed that soil compaction and water-stable aggregates in 0-50 cm depth had weak variability, with the variation coefficients of 9.9% and 4.9%, respectively. Soil bulk density had moderate variability, with the variation coefficient of 27.5%. Wheat yield and fertilizer partial factor productivity were negatively correlated with soil compaction, which were more closely correlated in soil depths of 0-10 cm, 10-20 cm and 20-35 cm. Results from multiple regression showed that wheat yield was determined by soil compaction and organic matter. The improvement of soil organic matter and reduction of soil compaction in top soil (0-20 cm) and plough pan layer (20-35 cm) would be the key strategies to enhance wheat yield in dark loessial soil on Weibei Plateau.

Can native shrubs facilitate the early establishment of contrasted co‐occurring oaks in Mediterranean grazed areas?

AbstractQuestionsCan shrubs (Cytisus multiflorus) and large herbivore exclusion (fence) facilitate seedling survival and growth of marcescent and sclerophyllous oaks (Quercus pyrenaica vs Q. ilex subsp. ballota) under a bioclimatic limit in Mediterranean grazed areas?LocationOpen oak woodlands, central‐western Spain.MethodsA 2‐yr field experiment was conducted by planting 200 seedlings of each Quercus species under four different treatments combining the influence of nurse shrubs and fencing on Quercus seedling survival and growth.ResultsCytisus multiflorus enhanced poor Quercus seedling survival found in the study area, at least during the first 2 yr after planting and particularly during the first dry season. The improvement in soil organic matter under the shrub canopy may have contributed to this positive effect, which was more pronounced on Q. pyrenaica seedlings. Seedling herbivory did not seem to be a limitation to survival. Increased seedling growth in both species was also very low, and no growth was recorded 2 yr after planting without shrubs. The positive shrub effect on seedling growth, especially marked in fenced areas, was more important in Q. pyrenaica in the first growing period and in Q. ilex in the second; 2 yr after planting no difference in shrub effect on growth was found in either Quercus species. Seedling herbivory was a limitation to seedling growth in areas without shrubs, mainly in the case of Q. pyrenaica.ConclusionsIn Mediterranean grazed areas with important summer drought and very sandy soil, shrubby C. multiflorus plants have a clear facilitative effect on seedlings of ecologically contrasted Quercus species. The facilitative effect was found in both marcescent and sclerophyllous oak seedlings, but to a different degree depending on the species considered and the variable measured (survival or growth). In terms of survival, the marcescent species was more favoured by shrub cover than the sclerophyllous one, and this effect was accentuated through time. However, in terms of growth, although Q. pyrenaica was initially more favoured by shrubs, differences between the two species were attenuated after 2 yr. Therefore, C. multiflorus can have a key role in restoration of these oak degraded environments.

Salinization/sodification of soil and physiological dynamics of sunflower irrigated with saline–sodic water amending by potassium and farm yard manure

Sunflower (Helianthus annuus L.) plants were grown with saline–sodic water (SSW) by treating with potassium (K @ 100 and 200 mg K2O kg−1 soil) and farm yard manure (FYM @ 5 and 10% of soil, w/w). Irrigation with untreated SSW caused soil salinization/sodification, leading to an increase in electrical conductivity (EC) of 165% and sodium adsorption ratio (SAR) 100% with the subsequent increase of 736% in shoot Na+, a decrease of 52% in shoot K+ and 94% in shoot K+:Na+ratio compared to canal water. SSW also decreased physiological activities: 31% relative water content (RWC), 34% membrane stability index (MSI), 51% protein, 33% chlorophyll and 58% photosynthetic rate compared to canal water. Integrated application of K and FYM, at higher level, decreased soil EC by 54% and SAR 43%, and shoot Na+ 57% with a corresponding improvement in soil organic matter 166%, shoot K+ 360%, shoot K+:Na+ratio 987%, RWC 34%, MSI 37%, protein 60%, photosynthetic rate 102%, superoxide dismutase 92%, peroxidase 78% and catalase 52% compared to SSW without K and/or FYM. In conclusion, exogenous application of K and FYM could be a promising approach to use brackish water in agriculture on a sustainable basis.

On-farm compost: a useful tool to improve soil quality under intensive farming systems

Conventional agriculture that uses extensive tillage without organic inputs to soils can cause a degradation in soil quality. The improvement of soil organic matter (SOM) content can be achieved through the use of organic amendments. Application of organic amendments, such as compost, is a reliable tool to improve soil quality. On-farm composting is an ecological technology and can be used to recycle agricultural waste materials, such as animal manure or crop residues, that can be incorporated into the soil to improve soil quality. Therefore, the objective of this work was to characterize, by CPMAS-NMR spectroscopy and chemical properties, a commercial organic waste compost and an on-farm compost and, then, to compare their use as organic amendments on soil quality. A greenhouse study on intensive agricultural soils of Southern Italy was done. The following amendments, as soil treatment, were used: a municipal compost (MC), with C:N 13.3, and an on-farm compost (OF), with C:N 17.1, applied at the rate of 8.5 and 6.0 Mg DMha−1, respectively. After one, four, eight, twelve and fifteen months soil samples were collected and analyzed for chemical (pH, electrical conductivity, limestone, CEC, available phosphorus, organic carbon, total nitrogen and exchangeable bases) and microbial (urease, phosphomonoesterase, β-glucosidase, total hydrolytic activity and Biolog Ecoplate™) properties. MC compost was characterized by larger electrical conductivity and exchangeable Na+ content with respect to OF compost, while this latter was characterized by about twice of organic carbon (470gkg−1). As showed by CPMAS-NMR spectroscopy, OF compost was characterized not only by cellulosic polysaccharides, but also significant amounts of both alkyl components and lignin derivatives. An effective increase of soil organic carbon (SOC) in plots under MC (+36%) and OF (+25%) composts, respectively, was reached at the end of the experiment. Soil amendments improved soil biological functions as revealed by a general trend of positive effects on hydrolase activity, phosphomonoesterase, β-glucosidase as well as urease. EC and exchangeable Na+ were considerably larger only in the plots under MC compost (25% and 19%, respectively), with respect to control plot. The possible increase of soil salinity after compost amendment may negatively affect soil quality in the long-term. In conclusion, our results demonstrated that the supply of compost produced on-farm, can enhance soil biological and biochemical properties, without the drawbacks of municipal composts, representing a promising alternative to the latter and an important way to reuse wastes produced by cultivation and processing of vegetables.

Soil properties and corn (Zea mays L.) production under manure application combined with deep tillage management in solonetzic soils of Songnen Plain, Northeast China

Poor soil structure and nutrients, excessive exchangeable Na+, high pH as well as low enzyme activities are common in the solonetz, and significantly restrict corn (Zea mays L.) production. Cattle manure application combined with deep tillage is an important management practice that can affect soil physico-chemical properties and enzyme activities as well as corn yield in the solonetz. Field experiments were carried out in a randomized complete block design comprising four treatments: Corn with conventional tillage was used as a control, and corn with manure application combined with deep tillage as well as film mulching and aluminium sulfate were used as the experimental treatments, respectively. The relationship between corn yield and measured soil properties was determined using stepwise regression analysis. Manure application combined with deep tillage management was more effective than conventional tillage for increasing corn yield and for improving soil properties in the solonetz. The highest corn yield was obtained in the treatments with manure application+deep tillage+plastic film mulching (11 472 and 12 228 kg ha−1), and increased by 38 and 43% comparing with the control treatment (8 343 and 8 552 kg ha−1) both in the 2013 and 2014 experiments, respectively. Using factor analysis, three factors were obtained, which represented soil fertility status, soil saline-alkaline properties and soil structural properties both in the 2013 and 2014 experiments, respectively. Manure and deep tillage management resulted in two distinct groups of soil properties: (1) soils with manure application combined with deep tillage and (2) soils with conventional tillage. Stepwise regression analysis showed that corn yield was significantly and positively correlated to urease and available P, as well as negatively correlated to pH, electrical conductivity (EC), exchange sodium percentage (ESP), and bulk density (ρb). We concluded that ρb was dominant factor for corn yield on the basis of discriminant coefficient. Manure application combined with deep tillage management resulted in an increase in corn yield mainly owing to improved soil structural properties, followed by decreased soil saline-alkaline obstacle as well as increased urease activity and available P. This result is likely that the improvement in soil organic matter (SOM) from manure application greatly and positively contributed to better soil physico-chemical properties and enzyme activities, especially decrease in ρb. Suggestion for corn production should be improvement in soil structural properties firstly. This could cause decrease in ρb that key factor which limited the corn production in the solonetz.

Effects of Management Practices on Soil Nutrient Levels in Sabke Catchment Area, Nigeria

In Nigeria’s drylands, profitable crop production requires adequate soil fertility management. This study examines the effects of farmer-managed practices on soil fertility in Sabke catchment of the drylands. Seven sites under permanent cropland, fallow land, grassland, shrubland, orchard land, intercropping land and woodland distributed on four transects were selected across the catchment. At every site, five replicate soil samples were collected from 0-15cm (topsoil) and 20-30cm (subsoil) and analysed for C, N, P, Ca, Mg, K and Na. Higher topsoil values of most of the properties were observed under cropland and intercropping sites. The two cultivated plots receive annual applications of organic manure in addition to chemical fertilizer and crops residue retention while the other plots are not. Thus, improvement in soil organic matter and nutrients would be expected in soils of the area with high rate of application of manure and chemical fertilizer, and retention of crop residues

Ecological Improvement of <i>Fraxinus </i><i>velutina</i> Forest on Heavy Saline-Alkali Soil

In order to discuss improving effect of ecological forest on heavy saline-alkali soil and to provide reference for biological improvement of saline-alkali soil, the soil chemical properties (pH, salt content, organic matter, available potassium and cation exchange capacity) of 20cm-depth in four different stages of growth on pure forest of Fraxinus velutina planted on heavy saline-alkali soil were studied. The results showed that pH value of forest soil in other stages of growth except defoliating stage was lower than that of CK, pH value in flowering stage decreased by 0.77 unit, and the decrease was the largest. The organic matter obviously increased in four different stages of growth, but the best effect of soil organic matter improvement was defoliating stage. During defoliating stage in mid-October, salt content of forest soil was 1/2 of CK, and cation exchange capacity was three point two nine times of CK. The available potassium of forest soil obviously increased in flowering stage and peak leafing stage. All in all, there was greater effect for the soil chemical properties of 20cm-depth in different growth stages of pure forest of Fraxinus velutina, so when salt-tolerance plant was used to improve saline-alkali soil, we should use scientific measure to cultivation and management in consideration of requirement of different growth stages of forest for soil water and soil nutrient in order to consolidate the improving achievements and to accelerate the improving process.

宁夏引黄灌区猪粪还田对稻作土壤硝态氮淋失的影响

PDF HTML阅读 XML下载 导出引用 引用提醒 宁夏引黄灌区猪粪还田对稻作土壤硝态氮淋失的影响 DOI: 10.5846/stxb201212271888 作者: 作者单位: 中国农业科学院农业环境与可持续发展研究所农业清洁流域团队,中国科学院地理科学与资源研究所生态网络观测与模拟重点实验室;中国科学院地理科学与资源研究所生态网络观测与模拟重点实验室,西北农林科技大学林学院，陕西杨凌 712100,中国农业科学院农业环境与可持续发展研究所农业清洁流域团队,中国农业科学院农业环境与可持续发展研究所农业清洁流域团队 作者简介: 通讯作者: 中图分类号: 基金项目: 环保公益性行业科研专项经费（201009017） Effect of nitrate nitrogen leaching of paddy field based on swing manure application in the Yellow River irrigation district of Ningxia Author: Affiliation: Agricultural Clear Watershed Group, Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences,,College of Agronomy, Northwest A &F University,Yangling , Shaanxi 712100 , China,Agricultural Clear Watershed Group, Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences (CAAS),Agricultural Clear Watershed Group, Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences (CAAS) Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:以宁夏引黄灌区稻田为例，探索猪粪还田条件下稻田土壤硝态氮淋失规律。试验设置3个处理：常规施肥300 kg纯 N kg/hm2（CK）、常规施肥条件下施用4500kg/hm2（T1）和9000 kg/hm2（T2）猪粪。利用树脂芯法吸附稻田30cm、60cm和90cm土层的硝态氮流失量。结果表明：在常规施肥的基础上增施猪粪，可以减少稻田生育期内60cm与90cm处土壤硝态氮淋失量，与CK相比，T1、T2在两个土层处淋失量的减少比例分别为4.93%、13.92%与7.48%、13.77%。同一土层不同处理之间差异显著性比较看（P < 0.05），30cm 处T1、T2与CK相比没有达到显著性差异；60cm处，T1与CK未达到显著差异，T2与CK达到显著差异；90cm处，T1、T2与CK相比达到显著差异；60cm和90cm土层处的T2与T1之间均达到显著差异。T1和T2在30cm处的淋失量高于CK，但增加不明显，处理之间以及处理与对照相比差异不显著。稻田生育期内不同土层硝态氮淋失量在13.61-17.77 kg/hm2（纯N）。硝态氮淋失集中在插秧至分蘖期（5月中旬-6月下旬），该阶段的硝态氮淋失量占生育期内总淋失量的61.62%-72.84%；后期淋失量明显减少。处理T1、T2的水稻产量增产率分别为15.86%与12.85%。由此可见，在引黄灌区稻田，一定数量的猪粪还田，不仅能够减少土壤硝态氮向深层淋失，防控地下水污染，还有利于水稻增产。 Abstract:The Yellow River irrigation district of Ningxia is an important agricultural area in North China, where the nitrate leaching and water pollution have been an increasing problem in recent year. Water in a number of drainage ditches is of Inferior quality, in which the main pollutants are nitrate and ammonium nitrogen. The concentration of ammonium is usually 20-30mg/L and can be much higher up to 70 mg/L in extreme cases, so that downstream water quality is severely affected. The proportion of total nitrogen and ammonia nitrogen from field was up to 61%-66% and 76%-81%, respectively. The concentration of nitrate nitrogen in about half of shallow groundwater was more than 10 mg/L. Content of soil organic matter, ranging from 9.2 to 14.5g/kg with the mean of 10.2 g/kg, was low; consequently it facilitates the loss of soil nutrient nitrate nitrogen. In this study, we investigated the effect of swine manure application in management of nitrate nitrogen leaching and improvement of soil organic matter in this area. The characters of nitrate nitrogen leaching in paddy fields in the Yellow River irrigation district of Ningxia were explored in the condition of swine manure application. The field experiment was conducted with 3 treatments: tradition fertilization without swine manure (CK), tradition fertilization with swine manure of 4500kg/hm2(T1)and tradition fertilization with swine manure of 9000 kg/hm2(T2). Nitrate nitrogen leaching rates were measured for 30, 60, 90 cm depth soil layer with a resin core absorption method. The results are shown as follows: (1) The treatments with swine manure application reduced the nitrate nitrogen leaching loss at 60 and 90 cm depth soil layers in the paddy field during rice growth period. The decreases were 4.93% (60 cm) and 13.92% (90 cm) for T1 vs. CK and 7.48% (60 cm) and 13.77% (90 cm) for T2 vs. CK. (2) In comparisons of the statistical significance of nitrogen leaching loss at the same soil layer between different treatments (P < 0.05), the variations among T1, T2 and CK were not significant at 30 cm depth. In the soil samples from 60 cm depth, T1 and CK were not significantly different, while T2 was significantly different from CK. Compared to CK, both T1 and T2 caused a significant reduction in nitrogen loss at 90 cm depth. Meanwhile, the difference between T1 and T2 were significant at 60 and 90 cm depth. Although the nitrate nitrogen leaching loss of T1 and T2 were higher than that of CK at 30 cm depth, the difference did not reach statistical significance among CK and T1 and T2. (3) The nitrate nitrogen leaching loss was 13.61-17.77 kg/hm2 (pure nitrogen) in different soil layers during rice growth period. The major loss accounting for 61.62%-72.84% of the whole growth period occurred during the time from rice transplantation to tillering, corresponding to the season from middle May to end of June, and the loss was obviously alleviated at the late stage of rice growth. (4) The rice yield in T1 and T2 was increased by 15.86% and 12.85%, respectively. Taken together, our study suggests that swine manure application is effective to prevent nitrate nitrogen leaching loss in the Yellow River irrigation district of Ningxia and beneficial to rice production as well. 参考文献 相似文献 引证文献

Potential for Increasing Soil Nutrient Availability via Soil Organic Matter Improvement Using Pseudo Panel Data

Fixed and random effect models were applied to a pseudo-panel data built of soil analysis reports from tobacco farms to analyze relationships between soil characteristics like soil organic matter (SOM) and soil nitrogen (N), phosphorous (P) and potassium (K) and to explore the potential for improving nutrients availability by increasing SOM content. These econometric models may account for unobserved specific characteristics such as location-specific characteristics, management strategies, farmers’ skills and preferences and environmental heterogeneity. Positive relationships were found between N, P and K availability and SOM. The random effect model reports a highly significant elasticity of N with respect to SOM of 0.75, meaning that an increase of 1% of SOM will increase soil N by 0.75%. Using this elasticity, the required SOM improvement of green manure was calculated at which costs of green manure would exactly equal benefits in terms of reduced N fertilizer use. Costs and benefits are equal if the SOM increases from 1.55% to 3.61%, which is barely achieved according to the literature. Hence, growing green manure crops to increase SOM and thereby N availability is not economically attractive. However, additional benefits may arise from SOM improvement and growing green manure crops.

Maximising yield benefits from dual-purpose cowpea

Cowpea (Vigna unguiculata [L.] Walp.) is consumed by many subsistence farmers across the African continent as a cheap source of quality protein. Harvest of cowpea leaves as a vegetable as well as grain from the same plant (dual-purpose) is a primary goal for farmers, which allows them to exploit the nutritional benefits of both. The leaves are consumed in a variety of traditional dishes, or dried for use in the dry season. However, leaf harvest practices by farmers are among the leading causes of poor grain yield and quality. These negative effects can extend to reduction in other benefits of cowpeas such as nitrogen fixation and soil organic matter improvement. This paper critically reviews the effects of leaf harvesting practices on cowpea crops and options available to subsistence farmers to mitigate the negative effects. Recommendations on appropriate timing, duration and intensity of leaf harvesting are then provided, together with agronomic strategies for maximising benefits. Information gaps are also highlighted with the aim of guiding future research programmes for the improvement of the food productivity of cowpea.

Growth and fruit yield of Pepper (Capsicum annum) as influenced by varying degree of pruning of Pigeon pea (Cajanus cajan) in a Pepper/Pigeon intercrop

study was conducted at the teaching and research farm of the University of Agriculture Abeokuta (7o15'N, 3o25'E) between May 2007 and January 2009. Five treatments arranged in Randomized complete block design (RCBD) and replicated three times comprised of pepper planted between rows of pigeon pea spaced at 25 x 150 cm and pruned to 25 cm, 50 cm, 75 cm and 100 cm above the soil surface and a sole pepper control. The intra and inter row spacing of pepper in sole and mixtures was 50 cm by 50 cm. Varying pruning regime of pigeon pea had no significant effect on growth, total fruit yield and number of fruits, monthly fruit yield and number of fruits and monthly fresh fruit weight of pepper. Number of fruits of pepper increased across all treatment and peaked in November, the same goes for pepper fruit yield. Pepper monthly fruit weight however declined continuously from point of first harvest. Fruit yield of pepper is influenced more by the number of fruits than the fruit weight. It was concluded that Mixture of pepper with pigeon pea pruned to 50 cm above the soil was the best treatment in this study. This treatment combines better (p>0.05) fruit yield of pepper with relatively longer (p>0.05) period of harvest with appreciably high biomass of pigeon pea for soil organic matter improvement .In pepper/pigeon pea intercrop pruning pigeon pea to about the average height of the pepper will be adequate for proper growth and fruit yield.

Microbial biomass carbon and microbial activities of soils receiving chemical fertilizers and organic amendments

Effect of chemical fertilizers and organic amendments on soil chemical and microbiological properties were studied in soils receiving these amendments over a period of 3 years under tropical conditions. Soil organic C and total N increased in treatments receiving a combination of organic amendments and different doses of chemical fertilizers compared to soils receiving chemical fertilizers alone. Mineral N and available P in the soil were greater with the integrated use of chemical fertilizers and organic inputs. Microbial biomass C increased significantly with the combined application of chemical fertilizers and organic amendments, in comparison to soils receiving chemical fertilizers alone. Dehydrogenase and alkaline phosphatase activities also increased with the application of farmyard manure and Sesbania aculeata green manure. The results indicated that there is improvement in soil organic matter, microbial activities and crop yields due to the use of chemical fertilizers along with organic manures. Such positive effects of organic inputs can help in maintaining organic matter level and sustain good crop yields over a period of time without deteriorating soil health.