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   173篇
  免费   10篇
  国内免费   4篇
林业   12篇
农学   7篇
基础科学   1篇
  60篇
综合类   12篇
农作物   19篇
水产渔业   6篇
畜牧兽医   40篇
园艺   5篇
植物保护   25篇
  2023年   7篇
  2022年   17篇
  2021年   11篇
  2020年   17篇
  2019年   15篇
  2018年   17篇
  2017年   19篇
  2016年   9篇
  2015年   7篇
  2014年   8篇
  2013年   8篇
  2012年   10篇
  2011年   10篇
  2010年   4篇
  2009年   3篇
  2008年   11篇
  2007年   3篇
  2006年   2篇
  2005年   2篇
  2003年   3篇
  1999年   1篇
  1998年   1篇
  1987年   1篇
  1982年   1篇
排序方式: 共有187条查询结果,搜索用时 15 毫秒
101.

Aims  

To promote the value of farm manure through investigating its effect on soil health using statistical methods.  相似文献   
102.
Journal of Plant Diseases and Protection - Bacterial wilt incited by Ralstonia solanacearum has been found the most damaging and widespread diseases of tomato throughout the world and causes heavy...  相似文献   
103.
The contamination of agriculture soils with heavy metals is increasing due to both natural and anthropogenic activities. This has resulted in lowering the yield and quality of agriculture crops. The aim of the present investigation was to determine the effect of Moringa oleifera (M. oleifera) aqueous leaf extract (MALE) on growth and Hg phytoextraction potential of maize cv. Azam under mercuric chloride (HgCl2)-induced stress. Soil was contaminated with different concentrations of HgCl2 (1 and 0.5?mg/kg). The MALE was applied at 5% and 2.5% as seed soaking prior to sowing of seeds in the pots. The M. oleifera leaf was a good source of macronutrients (Na, K, Ca and Mg) and micronutrients (Fe, Zn, Mn, Co and Ni) as well as natural phenolics. The induced HgCl2 stress significantly reduced seed germination (%), shoot dry weight, root dry weight, chlorophyll content and carotenoids content. The HgCl2-induced stress was associated with accumulation of phenolics and Hg in roots. The accumulation of Hg in roots was significantly correlated with phenolics content (r?=?.8007, p?=?.000). The exogenous application of MALE significantly ameliorated adverse effects of HgCl2 stress on maize plants. The accumulation of Hg in roots was significantly increased by MALE. It is inferred from findings of the present investigation that MALE served as bioregulator and can be applied to reduce adverse effects of HgCl2 on maize. Moreover, MALE can enhance the Hg phytoremediation potential of maize.  相似文献   
104.
This experiment was conducted to investigate the effects of biochars, produced from maize straw at different temperatures (300, 400, and 500 °C), on growth of maize. Maximum cation exchange capacity (CEC) (106 cmolc kg?1) of biochar was observed at 400 °C. The pH, electrical conductivity (EC), and carbon content of biochars significantly increased with increasing temperature, and maximum pH (9.8), EC (3.0 dS m?1), and carbon content (607 g kg?1) were observed at 500 °C. Concentration of phosphorus (P), potassium (K), calcium (Ca), and magnesium (Mg) significantly increased with increasing temperature, while of nitrogen (N) decreased. Ammonium bicarbonate–diethylene triamine penta acetic acid (AB-DTPA)–extractable nutrients were decreased with increasing pyrolysis temperature. Shoot and root dry matter of maize increased significantly with application of biochar produced at 300 and 400 °C and decreased significantly at 500 °C. Maximum shoot and root dry matter of maize was obtained at biochar produced at 300 °C. Phosphorus and K concentration in shoots and roots increased with biochar, and it was significantly more with fertilizer application. In contrast to P, shoot and root K concentration increased significantly with increasing pyrolysis temperature. The results of this study indicated that application of biochar produced at low pyrolysis temperature may be a practical approach to improve crop growth.  相似文献   
105.
Natural materials and plants have a long history of medical applications due to their broad range of favorable biological functions including biocompatibility, anti-bacterial, anti-oxidant and anti-inflammatory properties. Main objective of this study was to develop alginate-chitosan-hyaluronic acid (ACH) composite fibers with controlled drug release, and liquid retention properties for better moist wound healing. The dope comprising sodium alginate was extruded into calcium chloride (CaC12) coagulation bath. The developed calcium alginate fibers were then passed through a bath containing hydrolyzed chitosan and dip coated with hyaluronic acid for 24 hours. The resulting ACH composite fibers were then rinsed with deionized water and dried using acetone. These fibers were tested for tensile properties, % swelling, liquid absorption (g/g) and controlled drug release. The results concluded that ACH composite fibers can be produced by wet spinning and have adequate tensile properties, high % swelling, liquid absorption (g/g) and controlled release of hyaluronic acid for improved wound healing.  相似文献   
106.
Conservational tillage (CT) in combination with broad spectrum herbicide may be more efficient and economical in controlling weeds,reducing cost of cultivation,and enhancing wheat yield.Field experimen...  相似文献   
107.
Field experiments were conducted at Institute of Soil and Environmental Sciences, University of Agriculture, Faisalabad, Pakistan, to check the effect of polymer-coated diammonium phosphate (DAP) on maize–wheat cropping system. Different rates of polymer-coated and uncoated phosphorus (P) were applied first to maize then followed by wheat after harvesting of maize on same field. Results showed that application of 100% of recommended P from polymer-coated DAP increased plant height (10%), chlorophyll content (4%), biological yield (17%), grain yield (36%), agronomic efficiency (43%), and nitrogen, phosphorus, and potassium contents of maize produces, while in case of wheat 75% recommended P from polymer-coated DAP increased plant height (6%), chlorophyll content (18%), biological yield (20%), grain yield (14%), agronomic efficiency (72%), and nitrogen, phosphorus, and potassium contents of grains and straw as compared with uncoated DAP. So, it can be summarized that polymer-coated DAP can effectively improve growth, yield, and phosphorus-use efficiency of maize and wheat crop.  相似文献   
108.
Soil salinity is becoming a major problem due to a variety of natural and man-caused factors particularly in arid areas. The present study documented on the effect of nephthyl acetic acid (NAA) foliar spray on physiological attributes of maize including growth responses, osmolites, and antioxidant enzymatic activities of the selected maize varieties PSEV3-2(ES) and Sarhad yellow at vegetative stage exposed to different sodium chloride (NaCl) concentrations of 20mM to 100mM, through pot experiments. Osmolites and antioxidant enzymes serve as physiological markers for selected maize varieties under saline conditions. The maximum increase in osmolites and protein contents, Peroxidases (EC 1.11.1.x), Superoxide dismutase (EC 1.15.1.1), Catalse (EC 1.11.1.6) and Ascorbate peroxidase (EC 1.11.1.11) activities in Sarhad yellow indicating the tolerance level of this variety as compare to PSEV3-2(ES). It has been concluded that the reduction in growth responses due to salinity has been improved by the exogenous application of nephthyl acetic acid.  相似文献   
109.
Sewage contains several trace elements of environmental concern, and cadmium (Cd) is one of the most mobile elements in soil–plant system that can pose drastic effects on plants and human health due to its long persistence and non-biodegradability nature in environment. It is necessary to prevent its entry into food chain for better food quality and human health. Present study was designed to evaluate the effectiveness of different water management practices, viz. W1: flooding throughout the growing season, W2: flooding after 4 days of disappearance of standing water (DAD), W3: flooding till heading and after that flooding of soil after 4 days of DAD, W4: Aerobic condition throughout growing season (flooding after 8 days) for reducing Cd concentration in rice grain grown under varying levels of Cd (0, 20, 40 mg kg?1) spiked soil. Results revealed that grain yield declined with increasing Cd levels but maximum plant height (89.3 cm), straw yield (16.9 g) and grain yield (22.5 g pot?1) was observed where pots were flooded till heading and thereafter flooding. Cadmium concentration increased with increasing concentration of Cd in soil. Further, it is added that the lowest Cd concentration in shoot, grain and husk and translocation factor were observed under W3 when the soil was spiked with 40 mg kg?1. In crux, continuous flooding till heading and thereafter flooding after 4 DAD can significantly decrease the grain Cd concentration without compromise on yield.  相似文献   
110.
Sahiwal cow is Bos indicus which is an important dairy breed of tropical and sub‐tropical region. Research on reproduction is rare in this breed. The objectives of the present study were to determine the effect of Ovsynch (OVS) versus prostaglandin F (PG) protocol on estrus response and its intensity, ovulation rate, timing of ovulation and pregnancy per artificial insemination (AI) in Sahiwal cows. Experimental cows (n = 80) were of mixed parity, lactating, suckled, ≥120 days postpartum with body condition score 3.08 ± 0.34 and 375‐475 kg of body weight which were randomly assigned to receive either OVS (n = 46) or PG (n =34) protocol. Cows were inseminated twice at 12 and 24 h after second gonadotropin releasing hormone in the OVS group, and 72 and 84 h after administration of prostaglandin F in PG group, respectively. The results revealed that estrus response did not differ (P > 0.05) and was 87% in OVS and 78% in PG cows. Ovulation rate did not differ (P > 0.05) and was 50% in both, OVS and PG cows. The pregnancy per AI did not differ (P > 0.05) and was 43% in OVS compared to 31% in PG cows. It is concluded that estrus response, ovulation rate and pregnancy per AI of OVS protocol is the same as PG in Sahiwal cows.  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