首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   123篇
  免费   8篇
  国内免费   6篇
农学   7篇
基础科学   1篇
  85篇
综合类   24篇
农作物   4篇
水产渔业   2篇
畜牧兽医   4篇
园艺   5篇
植物保护   5篇
  2024年   1篇
  2023年   2篇
  2022年   4篇
  2021年   5篇
  2020年   7篇
  2019年   6篇
  2018年   7篇
  2017年   16篇
  2016年   13篇
  2015年   7篇
  2014年   5篇
  2013年   21篇
  2012年   19篇
  2011年   9篇
  2010年   6篇
  2009年   1篇
  2007年   1篇
  2006年   3篇
  2005年   3篇
  2003年   1篇
排序方式: 共有137条查询结果,搜索用时 46 毫秒
1.
The aim of this research was designed in order to optimize integrated plant nutrient supply (IPNS) through balanced fertilization of organic, inorganic and microbial inoculants in strawberry cv. Chandler. The potential efficiency of bio-organics used along with chemical fertilizers on cropping behaviour, physical-chemical and biological properties of rhizosphere soil, fruit yield, quality attributes and leaf nutrient content was investigated. The significant improvement in physico-chemical properties of the soil and nutrient uptake was recorded. The uninoculated control received farmyard manure (FYM) and inorganic nitrogen (N) recorded the highest cation exchange capacity (CEC) and soil organic carbon (OC) content. Highest available N and phosphorus (P) of soil were recorded in vermicompost and inorganic N applied in two and one split, respectively. The concentration of micronutrients cations viz., iron (Fe), zinc (Zn), manganese (Mn) in soil was higher in treatment received vermicompost and inorganic N in two splits. The integration of bio-organic nutrient supplements also significantly enriched the microbial status of the rhizosphere soil, leaf nutrient concentration and maintained soil health and productivity on long term basis for sustainable fruit production.  相似文献   
2.
[目的]探讨蚯蚓粪与化肥配施对西瓜种植的作用,为土壤培肥制度的建立及西瓜生产提供参考。[方法]以"黑彤K-8"为试材,通过大田试验研究了N100(尿素提供100%的氮)、M10N90(蚯蚓粪和尿素分别提供10%和90%的氮)、M30N70(蚯蚓粪和尿素分别提供30%和70%的氮)和M50N50(蚯蚓粪和尿素各提供50%的氮)等不同处理对土壤活性有机碳、碳库管理指数(CPMI)、酶活性和西瓜产量的影响。[结果]同N100处理相比,配施蚯蚓粪处理的高活性、中活性和活性有机碳含量均明显升高;M30N70处理的活性有机碳含量和CPMI显著高于其他处理,比N100处理分别高出30.10%和37.28%;同时,脲酶和蔗糖酶活性亦明显高于其它处理,其中蔗糖酶活性分别较CK,N100,M10N90和M50N50处理提高84.66%,62.33%,47.26%和22.46%。此外,M30N70处理的西瓜产量和肥料生产率最高,它可使西瓜产量分别比N100,M10N90和M50N50处理高出26.49%,13.34%,6.27%;M30N70处理的肥料生产率分别比N100,M10N90和M50N50处理高出166.50%,54.11%,21.37%。相关分析结果表明,运用土壤活性有机碳和碳库管理指数表征土壤酶活性、西瓜产量及肥料生产率的变化,比土壤总有机碳更具灵敏性。[结论]蚯蚓粪与化肥配施对西瓜生长具有显著的促进生长效果,其中3∶7比例配施的效果优于1∶9和5∶5比例。  相似文献   
3.
The effects of lower field rate (LFR), field rate (FR), and higher field rate (HFR) applications of carbofuran on ammonium (NH4)-nitrogen (N), nitrate (NO3)-N, available phosphorus (P), and available potassium (K) contents in natural soils and those amended with inorganic fertilizers and vermicompost on the growth of tomato plants were studied. The NH4-N, NO3-N, available P, and available K contents increased up to FR but the most significant increase in was observed at LFR of carbofuran application. At HFR there was a significant reduction in nutrient availability. With passage of time all these parameters increase up to 30 days; thereafter, a decrease was observed up to the end of the experiment in both unamended and amended soils. The greater plant growth was observed at LFR of carbofuran application and at HFR the plants exhibited phytotoxicity in the form of marginal leaf scorching in both systems. The morphological growth parameters of tomato plants were positively correlated with nutrients availability.  相似文献   
4.
Maintenance of tropical soil quality for crop production without damaging the environment is a challenge and thus the development of an efficient nutrient-management technique is important. Soil amendment by organic manures has been widely accepted as an efficient nutrient-management technique in tropical agriculture. In this study, a long-term laboratory experiment was conducted to investigate the influence of organic manures of different sources (e.g. cattle manure, poultry manure, vermicompost and oil cakes) on changes in pH, electrical conductivity, organic C and nutrient content (mineral N, available phosphorous and potassium) in tropical alluvial soil. Applications of organic amendments in this study indicated considerable changes in the basic soil physico-chemical properties and different nutrient levels. Soil pH declined slightly, whereas organic C and all the other nutrients increased distinctly, due to the application of organic manures. Thus, the magnitude of changes in the soil properties was dependent on the nature of the organic manure.  相似文献   
5.
A 2-year field study was conducted to evaluate the effect of two organics, farmyard manure and vermicompost, each at three rates (0, 5, 10 t ha?1 and 0, 1, 2 t ha?1, respectively), along with two levels of mineral fertilizer (75% and 100% of recommended dose), on crops yields and soil properties under a wheat–fodder maize cropping sequence. Individual addition of organics at a higher level increased yields of wheat and subsequent maize. Soil microbial biomass carbon was enhanced as both a direct and residual effect with the addition of farmyard manure followed by vermicompost and fertilizer treatments, and also by combined addition of manure with either vermicompost or mineral fertilizer. Farmyard manure increased the availability of soil macro- and micronutrients, whereas vermicompost influenced only the availability of micronutrients at wheat harvest. A residual effect of farmyard manure and mineral fertilizers was found for available N. Meanwhile, the residual status of micronutrients in the soil was either maintained or significantly improved due to organic amendments (Mn and Zn with farmyard manure; Fe and Zn with vermicompost). Interaction of farmyard manure and vermicompost at a higher level benefited the next crop by increasing the yield of fodder maize and improving the availability of P and metals in soil.  相似文献   
6.
Copper(Cu)-based fungicide application to control foliar diseases in grapevine(Vitis vinifera L.) can increase soil Cu availability. Brazilian soils have high natural Cu and manganese(Mn) concentrations, increasing the potential for toxicity to grapevine plants. Application of amendment substances can reduce the concentrations of toxic chemical species of Cu and Mn in soil solution, especially for the soils grown with young plants. We evaluated the chemical speciation of Cu and Mn in soil soluti...  相似文献   
7.
针对农田土壤镉(Cd)活性高的问题,以寻求具有良好重金属钝化特性的原位修复材料为目标,该研究以铁粉、磷矿粉和牛粪混合蚯蚓堆肥所制备的矿物基蚯蚓粪为研究对象,利用系列结构表征手段对其进行基本性质表征,并进一步分析矿物基蚯蚓粪施加下土壤对Cd吸附、有效性和赋存形态的影响,最终筛选出具有良好Cd钝化效果的矿物基蚯蚓粪。结果表明,铁粉及磷矿粉的添加使矿物基蚯蚓粪中的pH值、C/N、有机质含量有所降低,但总养分含量显著增加(P<0.05)。全自动比表面积及孔隙度、扫描电镜分析和X射线能谱分析结果表明,矿物质的添加增大了蚯蚓粪比表面积和孔容,改变了蚯蚓粪中矿物元素的占比。傅立叶变换红外光谱分析表明,矿物基蚯蚓粪中醇或羧酸类、芳香类以及多糖类物质增多,脂类和碳水化合物减少。X射线衍射分析表明,添加铁粉及磷矿粉制备出来的矿物基蚯蚓粪增加了磷酸盐、纳米零价铁等矿物组分。土壤培养和吸附解吸试验表明,施加矿物基蚯蚓粪显著提升了土壤对Cd的吸附强度,降低了对Cd的解吸率,其中以牛粪+20%铁粉+20%磷矿粉(VCFe+P)进行蚯蚓堆肥所获得的矿物基蚯蚓粪处理的土壤对Cd的吸附效果最佳,较施加纯蚯蚓粪的土壤吸附容量提升137.66%,解吸率降低7.34%~12.76%;该处理的土壤Cd钝化率高达50.02%,Tessier 形态分析结果表明,VCFe+P矿物基蚯蚓粪使交换态Cd向铁锰氧化态Cd和残渣态转化。综上,20%铁粉+20%磷矿粉+牛粪混合蚯蚓堆肥所制备的矿物基蚯蚓粪具有良好的Cd吸附表面特征和高效的Cd钝化能力,在土壤Cd污染修复方面具有较大的应用前景。  相似文献   
8.
Field experiments were conducted at the Crop Research and Seed Multiplication Farm of Burdwan University, Burdwan, West Bengal, India, to evaluate the influence of integrated nutrient management on soil physicochemical properties in a mustard (Brassica campestris cv. ‘B9’) cropping system. The experiment was conducted during the winter seasons of 2011–2012 and 2012–2013 in old alluvial soil (pH 6–7). Seven different doses of biofertilizers (Azotobacter and phosphate solubilizing bacteria (PSB)), vermicomposts, organic (cow dung), and chemical fertilizers were applied on mustard in both the experimental seasons. The results indicated an improvement in soil quality by increasing soil porosity and water holding capacity significantly, as well as gradual build-up of the soil micronutrient status after harvesting of the crop. Dual applications of biofertilizers and vermicomposts have contributed significantly to higher soil organic matter, available nitrogen (N), phosphorus (P), and potassium (K) contents as well as micronutrient availability of iron (Fe), manganese (Mn), zinc (Zn), and copper (Cu) and subsequently increased the soil health.  相似文献   
9.
Application of organic fertilizers in sustainable agriculture systems improves yield sustainability of field crop production. The current research has been formed to investigate the effects of various levels of vermicompost (zero, 3, 6 and 9 t ha?1) in combination with foliar spraying of potassium humate (0, 1, 2 and 3 mL L?1) on spring safflower, in Iran during 2012–2013. In addition, inorganic fertilization has been considered as conventional agriculture (CA). In the current experiment, growth indices, seed yield, yield components and flower yield were evaluated. The results showed that the maximum leaf area index, total dry weight and crop growth rate have been determined at 9 t ha?1 vermicompost and 3 mL L?1 K-humate while the maximum netto assimilation rate has existed in CA at the emergence of flower buds. Likewise, the results indicated that vermicompost leads to a significant increase in seed yield, flower yield and yield components except 1000 seed weight. Flower yield, head number per plant and seed number per head were affected by K-humate concentrations and increased significantly from 1 to 3 mL L?1. It should be mentioned that 9 t ha?1 vermicompost and 3 mL L?1 K-humate produced the highest seed and flower yield.  相似文献   
10.
Soil degradation in the semi-arid tropics (SAT) is mainly responsible for low crop and water productivity. In Madhya Pradesh and Rajasthan states in India, the soil analyses of farmers’ fields revealed widespread deficiencies of S (9–96%), B (17–100%) and Zn (22–97%) along with that of P (25–92%). Soil organic C was deficient in 7–84% fields indicating specifically N deficiencies and poor soil health in general. During on-farm evaluations in rainy seasons 2010 and 2011, the soil test based addition of deficient nutrient fertilizers as balanced nutrition (BN) increased crop yields by 6–40% (benefit to cost ratios of 0.81–4.28) through enhanced rainwater use efficiency. The integrated nutrient management (INM), however, decreased the use of chemical fertilizers in BN by up to 50% through on-farm produced vermicompost and recorded yields at par or more than BN with far better benefit to cost ratios (2.26–10.2). Soybean grain S and Zn contents improved with INM. Applied S, B, Zn and vermicompost showed residual benefits as increased crop yields for succeeding three seasons. Hence, results showed INM/BN was economically beneficial for producing more food, while leading to resilience building of SAT production systems.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号