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1.
The use of cow dung as a source of plant nutrients is widespread among many smallholder farmers in Ghana. The benefits of cow dung application in crop production depend on the amount, quality, nutrient-release patterns, and uptake by crops. Samples of cow dung from three main systems of manure management (free range, semi-intensive, and intensive) were collected from the Kumasi Metropolis in the semideciduous forest zone of Ghana and analyzed for nitrogen (N), carbon (C), phosphorus (P), potassium (K), calcium (Ca), magnesium, (Mg), and ash contents. This research was undertaken to corroborate results of an earlier study in the interior savanna zone of Ghana, because manure quality is a function of its management (handling, storage, and transport), animal breed, and vegetation type (feed). Nitrogen content varied from 1.44 to 2.10% with the intensive system of management recording the greatest value. Phosphorus varied from 0.48% under free-range (field) system to 0.80% under the intensive system. The greatest and lowest total K values of 1.74% and 1.11% were respectively recorded under the intensive and free-range management systems. Generally, the study indicated there was relatively better manure quality under the intensive system than in the semi-intensive and free-range (field) systems. The cow dung collected under the various manure-management systems was then incubated in a laboratory study to assess their nutrient-release patterns. The results revealed that the manure under the intensive system mineralized ammonium N during the first 6 weeks of incubation with peak mineralization in the fourth week. Immobilization of nitrate N was observed from the second to the eighth week of incubation from cow dung under all the management systems. Total N [nitrate (NO3?) + ammonium (NH4+)] was immobilized under the free-range and semi-intensive management systems throughout the incubation period except in the first week. Peak net N mineralization was observed during the fourth week of incubation from cow dung under the intensive system of manure management. Results of the study suggested that total mineral N needs of crops might not be met entirely through application of cow dung to Ferric Acrisol due to immobilization during appreciable period of decomposition of the manure.  相似文献   

2.
A 2-year field experiment was conducted to evaluate the single- and combined-application effects of cattle manure and urea on corn (Zea mays L.) production. A randomized complete block design was conducted with five nitrogen (N) rates (36, 72, 108, 144, and 180 kg N ha?1) as urea, cattle manure, or both. The stover yield and aboveground biomass increased with urea application up to 144 kg N ha?1 but remained unchanged at greater N rates. At all N rates, combined application of manure and urea resulted in greater grain yields than single applications. Crop response to applied N was greater in the combined N application system than in the single-application treatments. The greatest grain yield was found in plots that had received a combination of 18 ton manure ha?1 plus 160 kg urea ha?1. Manure application along with urea enhanced crop yield response to urea and reduced its application rate.  相似文献   

3.
ABSTRACT

Grain yield in many soybean experiments fails to respond to fertilizer nitrogen (N). A few positive responses have been reported when soybean were grown in the southern U.S., when N was applied near flowering and when biosolids were added. In a previous study, low N concentrations of soybean forage in north Texas on a high pH calcareous soil were reported and thus, we suspected a N nutrition problem. Consequently, we initiated this study to determine whether selected preplant N sources broadcast and incorporated into a Houston Black clay (fine, smectitic, thermic Udic Haplusterts) might increase forage N concentration, forage yield, or soybean grain yield. In 2003, N was applied as ammonium nitrate (NH4NO3, AN) up to 112 kg N ha? 1 and dairy manure compost (DMC) was applied at rates of 4.9, 9.9, 15.0, and 19.9 Mg ha? 1. The DMC contained 5.9, 2.6, and 6.7 g kg? 1 of total N, P, and K, respectively; thus DMC added 29 to 116 kg N ha? 1. In 2004, AN was applied at rates of 112 and 224 kg N ha? 1 and DMC was applied at 28 and 57 Mg ha? 1; thus, DMC added 168 to 335 kg N ha? 1. In another 2004 test, biosolids, a biosolids/municipal yard waste compost mixture (BYWC), and AN were compared. The biosolids contained 31, 18, and 2.9 g kg? 1 total N, P, and K, respectively. The BYWC mixture contained 8.8, 6.1, and 3.4 g kg? 1 of total N, P, and K, respectively. Biosolids were applied at 10 Mg ha? 1 (310 kg N ha? 1), BYWC was applied at 58 Mg ha? 1 (510 kg N ha? 1), and AN up to 224 kg N ha? 1. None of the soil treatments increased soybean grain yield or forage yield although AN slightly increased forage N concentration in 2003.  相似文献   

4.
Soil heterogeneity is one of the several factors that explain within-field variations in crop yielding. To overcome this problem, an experiment was conducted within the University of Ibadan to identify the zones with similar soil properties that can be managed uniformly to optimize crop yield. A total of 62 soil samples were collected from 6.5 ha of farmland based on the differences in slope, soil moisture regime, land management and cropping pattern. The spatial distributions of soil properties were mapped out using the Inverse Distance Weighing (IDW) interpolation technique and the results were subsequently reclassified into different soil management categories. The results showed that the farmland consists of four classes of total nitrogen (N), phosphorus (P) and soil bulk density (SBD); three classes of carbon (C) and volumetric moisture content (?); two classes of soil pH; and one class of soil texture. Each of the soil management maps was subsequently overlaid on each other to produce four specific site management units (SSMUs) for vegetable cultivation. The four SSMUs consisted of highly suitable units occupying 0.143 ha, marginally suitable unit occupying 0.971 ha, moderately suitable unit occupying 0.517 ha and unsuitable unit occupying 4.9 ha of land. The SSMUs will alleviate problems of reduced yield due to over- or under-applications of agrochemicals.  相似文献   

5.
利用香蕉茎秆与鸡粪为底料进行了C/N分别为15.2、21.5、25.5、31.8、41.5的堆肥对比试验,定量化研究了堆肥过程中堆体的温度、水分、pH和EC、全碳、全氮及C/N、养分有效含量随时间的变化规律。结果表明,堆体初始C/N在20~40范围内,均能成功地进行好氧堆肥。当C/N低于15.2时,堆体温度上升快,但高温持续时间短,pH高,水溶性盐分的含量高,有机质和总养分含量较低,而且由于加入鸡粪太多,增加了堆肥的成本;当C/N大于41.5时,堆体温度上升慢,进入高温期所需时间长,堆体含水率过高。综合考虑各方面因素,堆肥初始C/N控制在20~30为宜,以25.5为最佳;腐熟期为27d左右,对应适宜的C/N判断值为18。  相似文献   

6.
Manure urea pellets were produced and their nitrogen release rate was evaluated in soil incubation at different water contents of 90, 75, and 60% soil filed capacity (FC). In another experiment, sweet basil growth was evaluated during eight months (with three shoot harvests) under the pellet application. The nitrogen release and pellet dispersion rates were slow after two months or at lower soil water content (60% FC), but they were significant after four months of soil incubation, or at higher soil water content (75 or particularly 90% FC). Application of pelleted urea reduced plant growth and yield at first harvest than urea treatment. However, at second and particularly at third harvest (and the average of three harvests) significant improvement in growth parameters of SPAD value, leaf area, plant height, shoot fresh weight, pot yield, and` leaf N and K concentrations were achieved by application of pelleted urea fertilization.  相似文献   

7.
This experiment tested whether it was possible to incorporate broiler litter (BL) or cattle farmyard manure (FYM) into a 7‐yr arable rotation on a sandy soil without causing an increase in nitrate‐nitrogen (NO3‐N) leaching. Four manure treatments (with adjusted fertilizer inputs), varying in frequency and timing of application, were imposed on the rotation and compared with a control that received inorganic fertilizer according to recommended rates. Over seven winters, the annual average NO3‐N leached from the inorganic fertilizer treatment (control) was 39 kg/ha in 183 mm drainage. Total manure N loadings over the period of the experiment ranged between 557 and 1719 kg/ha (80–246 kg/ha/yr) for the four treatments. Three of the four manure treatments significantly increased NO3‐N leaching over the rotation (< 0.001). Annual applications of FYM (1719 kg/ha manure N or 246 kg/ha/yr) increased NO3‐N leaching by 39%. We hypothesize that this was due to increased mineralization of the organic N accumulating from repeated FYM applications. BL applied each year (1526 kg/ha manure N or 218 kg N/ha/yr) increased NO3‐N leaching by 52% above the control; BL applied 5 of 7 yr (972 kg/ha manure N or 139 kg N/ha/yr on average) and including inadvisable autumn applications increased leaching by 50%. BL applied in late winter or early spring every 2–3 yr (557 kg/ha manure N or 80 kg N/ha/yr on average) resulted in NO3‐N leaching similar to the control. This suggests that to avoid additional NO3‐N leaching from manure use in an arable rotation, manure should not be applied every year and autumn applications should be avoided; there are real challenges where manure is used on an annual basis.  相似文献   

8.
9.
李超  王俊  邢文超  张少宏  柳瑞 《水土保持通报》2022,42(2):107-113,121
[目的]探讨绿肥填闲种植对旱作冬小麦农田耕层土壤物理性质的影响,为其在黄土高原旱作农业区的推广提供科学依据。[方法]基于4 a田间定位试验,研究了夏闲期种植长武怀豆、苏丹草、怀豆/苏丹草混播以及裸地休闲(CK)对旱作冬小麦收获期农田耕层(0—20 cm)土壤容重、孔隙度、持水量和团聚体的影响。[结果]在0—10 cm土层,与CK相比,苏丹草和混播处理显著降低了土壤容重,怀豆,苏丹草和混播处理显著提高了土壤毛管孔隙度、总孔隙度、饱和持水量、毛管持水量、大团聚体(>5 mm)所占比例和团聚体平均重量直径(MWD);在10—20 cm土层,苏丹草处理大团聚体所占比例和MWD均显著高于CK。土壤容重与土壤有机碳含量呈显著负相关,毛管孔隙度和团聚体平均重量与绿肥生物量呈显著正相关,而土壤总孔隙度、饱和持水量和毛管持水量与绿肥生物量和土壤有机碳均呈显著正相关。[结论]在黄土高原地区,夏闲期单播种植长武怀豆、苏丹草及混播均能显著改善耕层土壤物理性质,综合来看,苏丹草单播的效果优于长武怀豆单播和二者混播。  相似文献   

10.
Precise quantification of nitrogen (N) mineralization in animal manure from different productivity-level management zones (MZs) could result in efficient and safe utilization of manure as N fertilizer. The objective of this study was to compare N mineralization rates of dairy cattle manure within and across three productivity-level MZs. To accomplish this, a 120 day laboratory incubation study was conducted at the Natural Resources Ecology Laboratory at Colorado State University using a completely randomized design set as a 2 factor factorial. Treatments for the study, which included the field equivalent of, 22, 44, 67, and 134 Mg ha?1 of applied animal manure, were replicated four times. Soils used in the study were collected from the top 15 cm of high, medium and low MZs from Fort Collins, Colorado, USA on a continuous corn (Zea mays L.) field. A significant difference (P ≤ 0.05) in mineralized N across MZs was found across manure rates. The high, medium and low MZ N mineralization rates were compared and there was no significant difference in cumulative N mineralized between MZs over time. The lack of statistical difference in mineralized N between MZs is hypothesized to have been influenced by the lack of substantial difference in soil pH and particle sizes (only 6% clay difference between MZs). That being the case, a study involving spatially variable soils with significantly different soil particle size between MZs may result in a different conclusion. The results of the study support the hypothesis that variable rates of manure mineralize differently within MZs; however, the results do not support the hypothesis that variable rates of manure in soil may mineralize differently across MZs.  相似文献   

11.
针对传统农业的局限性,探讨了传统农业生产模式转变为以信息网络为中心的精准农业的生产模式,阐述了ZigBee技术在精准农业中的应用,对系统的硬件进行了设计,并给出了软件流程。运用该系统可有效地降低成本,提高农作物产量。  相似文献   

12.
尿素与有机肥配施对棕红壤氮素转化的影响   总被引:2,自引:0,他引:2  
为了解析尿素配施有机肥对土壤氮库活动的影响,通过室内恒温培养试验研究尿素(225kg N·hm~(-2))分别与低量(30 t·hm~(-2))、中量(60 t·hm~(-2))及高量(120、150 t·hm~(-2))有机肥配施条件下棕红壤有机氮库、无机氮库的动态变化。结果表明,配施有机肥土壤的有机氮含量较单施尿素增加16.3%~85.6%。中、高量配施显著提高土壤氮素矿化速率(p0.05),加剧无机氮转化强度,与单施尿素相比,无机氮最大矿化量增加52.9~246.0 mg·kg~(-1),有效矿化持续时间延长5 d,转化量增大2.3倍~8.7倍;配施有机肥提高土壤氨化强度,加快铵态氮(NH_4~+-N)转化速率。与单施尿素相比,配施有机肥处理NH_4~+-N含量峰值增加2.6~42.6 mg·kg~(-1),平均氨化速率提高7.8 mg·kg~(-1)·d~(-1),转化速率增加1.4倍~8.8倍。一定量配施有机肥(30~120 t·hm~(-2))对土壤的硝化过程无显著影响,但过高量配施有机肥(150 t·hm~(-2)),强化土壤硝化作用,硝化速率较单施尿素提高4.2倍,引起土壤硝态氮(NO-3-N)大量累积。氮素表观平衡结果表明,中、高量配施有机肥显著增加培养体系氮素表观损失,60、90和120 t·hm~(-2)处理氮素损失量分别较单施尿素增加2.2倍、2.8倍和2.3倍,占总输入氮的27.5%~34.5%,其中,NH_4~+-N转化损失是体系氮表观损失的主要途径。本研究结果为棕红壤合理培肥提供了理论依据。  相似文献   

13.
采用田间试验结合15 N同位素示踪,研究有机无机肥配施对浙江省杭嘉湖平原稻田氮素利用率及环境效应的影响,结果表明:在施氮量150kg/hm2基础上,加施有机肥3 000kg/hm2,稻谷增产9.8%~17.7%,氮素利用率达到47.9%,比单施化肥提高4.8%。而在施氮量210kg/hm2的基础上增施有机肥,稻谷产量及氮素利用率均呈下降趋势。硝态氮是稻田土壤氮素损失的主要形式,施用有机肥能有效地降低氮素损失率。在施氮量150kg/hm2基础上配施有机肥,氮素通过田间径流的流失率由0.85%降至0.70%,氮素通过渗漏水损失率由1.29%降至0.96%;施氮量达到210kg/hm2后,施用有机肥对减少氮素流失的效果不明显。综合考虑试验点土壤特性、施肥目标产量以及对农田环境污染的潜在风险,建议以每1hm2施用纯氮150kg、配施3 000kg有机肥较为适宜。  相似文献   

14.
Green manure crops can be used as alternatives to mineral fertilizers because they improve soil structure and nutrient content of soil. Here, we evaluated the effect of partial replacement of mineral nitrogen (N) fertilizer with rapeseed residue green manure on soil properties and rice productivity in a rice–rapeseed double-cropping system. The treatments were comprised of four levels of mineral N fertilizer and recommended levels of phosphate and potash fertilizers. Rice clum and panicle length did not differ between treatments. However, the proportion of ripened grains and 1,000-grain weight of rice plants were greater under rapeseed residue amendments than those under 100% conventional mineral N fertilizer treatments. Paddy soils treated with rapeseed residues had greater soil organic matter and exchangeable cations than those treated with mineral N fertilizer alone. Thus, rapeseed residues applied as green manure can serve as alternative N sources in sustainable rice–rapeseed double-cropping systems.  相似文献   

15.
采用土柱培养的模拟试验方法研究了在不同磷水平土壤上大量施用磷肥和有机肥对土壤测试磷、土壤磷渗漏的影响及影响机理。结果表明,不同磷水平土壤施用磷肥或有机肥土壤CaCl2-P、Olsen—P和土壤渗漏液中可溶性磷均显著增加;单位量磷肥或有机肥所增加土壤各形态磷量随土壤磷水平的增加而增大;随着磷肥或有机肥用量的增加,单位量磷肥或有机肥所增加各形态磷量也逐渐增大,差异均达到显著和极显著水平。在施用磷肥的基础上增施有机肥可以提高土壤CaCl2-P、Olsen—P含量和土壤渗漏液中可溶性磷的增长幅度。土壤磷的渗漏量与土壤测试磷呈显著正相关;单位量磷肥或有机肥所增加的土壤渗漏磷量随着磷肥或有机肥用量以及土壤磷水平的增加而增加。Olsen—P含量与土壤磷吸持指数(PSI)呈显著负相关关系,与土壤磷的吸附饱和度(DPS)呈显著正相关关系。  相似文献   

16.
露天鸡粪好氧堆肥氮素的径流及淋洗损失   总被引:4,自引:0,他引:4  
在露天自然条件下对鸡粪进行好氧堆肥,系统研究了堆肥过程中氮素的径流和淋洗损失。结果表明,堆肥期间通过径流损失的氮素只占初始堆肥氮素的3‰~6‰,其中无机氮与有机氮约各占50%,径流中总氮浓度在不同时间和降雨量条件下差异较大,浓度平均在20 mg/L左右;氮素表现出很强的空间移动性,堆肥期间氮素至少能够迁移至150 cm土层,对当地地下水安全构成了严重威胁;堆肥过程中可能有35%~65%的氮素会通过氨挥发损失;用秸秆覆盖堆体能显著降低堆肥氮素的径流损失,而添加沸石减少堆肥氮素损失的效果不显著。  相似文献   

17.
利用田间小区试验,研究了有机无机肥配合施用模式对番茄产量、品质及氮素在土壤中累积和淋失的影响。结果表明:(1)与肥料用量较高的习惯施肥处理相比,大幅减少肥料施用的不同有机无机肥配合施用模式均能保证番茄产量稳定,显著提高经济效益,平均增收19127元·hm^-2其中(3/4)化肥N+(1/4)猪粪N模式处理经济效益最高。(2)施用有机肥的3个有机无机肥配合施用模式处理可降低番茄果实中的硝酸盐含量,较全部施用化肥处理和习惯施肥处理的分别降低5.4%和7.0%;施用有机肥的3个有机无机肥料配合施用模式处理可提高番茄果实中Vc的含量,较全部施用化肥处理的提高9.4%。(3)与番茄种植前相比,番茄收获后土壤硝态氮含量总体上表现出表层增加、深层降低的趋势;大幅减施肥料的有机无机肥配合施用模式处理各土层硝态氮含量均低于习惯施肥处理相应土层硝态氮含量。(4)有机无机肥配合施用模式可显著降低渗漏水中硝态氮渗漏量,较全部施用化肥处理和习惯施肥处理的平均分别降低35.5%和55.1%。在试验条件下,综合考虑产量、经济效益和环境效益的适宜有机无机肥料配合施用模式为(3/4)化肥N+(1/4)猪粪N模式处理。  相似文献   

18.
Agricultural land degradation due to nutrient deficiencies is a threat to agricultural sustainability. As nutrients availability is influenced by soil heterogeneity, climatic conditions and anthropogenic activities; hence, delineation of nutrient management zones (MZs) based on spatial variability could be an effective management option at regional scale. Thus, the present study was carried out to delineate MZs in the Shiwalik Himalayan region of India by capturing spatial variability of soil properties and secondary and micronutrients status because of the emerging nutrient deficiencies. For the study, a total of 2575 geo‐referenced representative surface (0–15 cm depth) soil samples were collected from the study region covering an area of 53,483 km2. The soils were analysed for pH, electrical conductivity, soil organic carbon, available sulphur (S) and micronutrients (Zn, Fe, Cu, Mn, B and Mo) concentrations. There was a wide variation in soil properties with coefficient of variation values of 14 (for pH) to 86% for available Mo. Geostatistical analysis revealed spherical, Gaussian, exponential, stable, circular and K‐Bessel best‐fit models for soil properties. Most of the soil properties were having moderate spatial dependence except soil pH and S (strong spatial dependence) and Zn (weak spatial dependence). About 49%, 10%, 2%, 13%, 11%, 12% and 8% area of the study region were found to be deficient (including acute and marginal deficiency) in S, Zn, Fe, Cu, Mn, B and Mo, respectively. The principal component analysis and fuzzy c‐mean clustering were performed to develop the MZs. Four principal components with eigenvalues greater than 1 and accounting 65·4% of total variance were retained for further analysis. On the basis of fuzzy performance index and normalized classification entropy, four potential MZs were identified. Analysis of variance confirmed the heterogeneity in most of the studied soil properties among the MZs. The study indicated that the methodology of delineating MZs can be effectively used in site‐specific S and micronutrients management in the Shiwalik Himalayan region of India. Copyright © 2016 John Wiley & Sons, Ltd.  相似文献   

19.
基于GPS和GIS的精细农业信息处理系统研究   总被引:21,自引:7,他引:21  
何勇  方慧  冯雷 《农业工程学报》2002,18(1):145-149
为了解决精细农业中空间信息的快速获取与分析处理问题,研究了一种用MapObjects实现GIS与GPS有机结合的信息处理系统,具有空间数据可视化分析处理,实时测定和显示动点轨迹,并具有计算面积等功能,能很好地与专家系统和决策支持系统等结合。为展开精细农业的研究,提供了一种新的信息处理方法和系统  相似文献   

20.
对我国未来精准农业发展的思考   总被引:4,自引:0,他引:4  
从保证国家粮食安全、解决资源环境问题的角度阐述了我国发展精准农业的重要性,分析了当前我国精准农业发展需要关注的6个问题,即突破精准农业关键技术瓶颈、降低精准农业技术应用的门槛、紧密与当地农业主导产业结合、采用因地制宜的技术应用模式、采取高效灵活的技术推广模式和制定精准农业技术标准。提出了今后我国精准农业发展战略的重点为构建具有自主知识产权的精准农业技术体系、具有中国特色的精准技术应用体系、学科交叉的精准农业人才体系。  相似文献   

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