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51.
连续稻茬油菜免耕对土壤理化性状影响的研究 总被引:3,自引:0,他引:3
[目的]探讨稻茬油菜免耕栽培机理。[方法]对连续多年免耕土壤进行取样,分析稻田油菜免耕土壤的各项理化性状指标,分析其对土壤结构性状的影响。[结果]免耕模式可以明显改善土壤的物理性状,对表层土容重的改善和土壤微团聚体含量的增加有积极的作用,有利增加土壤含水量,土壤总孔隙度呈逐年下降趋势。免耕模式还能够增加土壤有机质含量,有利肥沃土壤及作物生长发育,还能减小pH值却不至于酸化土壤,但是对土壤速效养分的影响却不明显。免耕土壤的速效养分均逐年上升,虽增幅不大但仍大于对照。表土层速效氮平均每年增加2.5 mg/kg,速效磷每年增幅为2.0 mg/kg,速效钾为1.25 mg/kg。[结论]该研究为大面积稻茬油菜免耕技术支撑提供理论依据。 相似文献
52.
R. Roscoe C. A. Vasconcellos A. E. Furtini-Neto G. A. A. Guedes L. A. Fernandes 《Biology and Fertility of Soils》2000,32(1):52-59
We studied the relationship between urease activity (UA) and soil organic matter (SOM), microbial biomass N (Nbiom) content, and urea-N fertilizer assimilation by maize in a Dark Red Latosol (Typic Haplustox) cultivated for 9 years under
no-tillage (NT), tillage with a disc plough (DP), and tillage with a moldboard plough (MP). Two soil depths were sampled (0–7.5 cm
and 7.5–15 cm) at 4 different times during the crop cycle. Urea was applied at four different rates, ranging from 0 to 240 kg
N ha–1. The levels of fertilizer N did not affect the UA, SOM content, and Nbiom content. No significant difference between the treatments (NT, DP, and MP) was observed for SOM during the experiment, probably
because the major part of the SOM was in recalcitrant pools, since the area was previously cultivated (conventional tillage)
for 20 years. The Nbiom content explained 97% and 69% of the variation in UA in the upper and deeper soil layer, respectively. UA and biomass N were
significantly higher in the NT system compared to the DP and MP systems. The highest maize productivity and urea-N recovery
was also observed for the NT system. We observed that the increase in urea-N losses under NT, possibly as a consequence of
a higher UA, was compensated for by the increase in N immobilized in the biomass.
Received: 2 July 1999 相似文献
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54.
Qingjie Wang Yuhua Bai Huanwen Gao Jin He Hao Chen R.C. Chesney N.J. Kuhn Hongwen Li 《Geoderma》2008,144(3-4):502-508
Data from a 16-year field experiment conducted in Shanxi, on the Chinese Loess Plateau, were used to compare the long-term effects of no-tillage with straw cover (NTSC) and traditional tillage with straw removal (TTSR) in a winter wheat (Triticum aestivum L.) monoculture. Long-term no-tillage with straw cover increased SOM by 21.7% and TN by 51.0% at 0–10 cm depth and available P by 97.3% at 0–5 cm depth compared to traditional tillage. Soil microbial biomass C and N increased by 135.3% and 104.4% with NTSC compared to TTSR for 0–10 cm depth, respectively. Under NTSC, the metabolic quotient (CO2 evolved per unit of MBC) decreased by 45.1% on average in the top 10 cm soil layer, which suggests that TTSR produced a microbial pool that was more metabolically active than under NTSC. Consequently, winter wheat yield was about 15.5% higher under NTSC than under TTSR. The data collected from our 16-year experiment show that NTSC is a more sustainable farming system which can improve soil chemical properties, microbial biomass and activity, and thus increase crop yield in the rainfed dryland farming areas of northern China. The soil processes responsible for the improved yields and soil quality, in particular soil organic matter, require further research. 相似文献
55.
Improvements in the yield potential of corn (Zea mays L.) grown using conservation-tillage may depend, in part, on K fertility management. Field research was conducted in 1997 and 1998 on a field which had been in continuous no-tillage (NT) for the previous 12 years near Paris, Ont., Canada to evaluate potassium (KCl) placement effects on corn growth and yields in NT, spring zone-tillage (ZT) and spring mulch-tillage (MT) systems. Soils were classified as moderately well drained and had low soil-test K levels. Potassium was spring-applied (1 day prior to corn planting) at either 0 or 100 kg K ha−1. Potassium was either broadcast applied, deep in-row banded (15 cm deep), or half broadcast applied and half shallow-banded (5 cm beside the row, 5 cm below seeding depth). Early season and mid-season corn ear-leaf K concentrations indicated that spring-applied K fertilizer was available for uptake by corn in conservation-tillage systems. Potassium application sometimes significantly increased corn yields compared to the zero K control in the NT and ZT systems. However, MT corn yields did not show any response to K fertilization in either season despite the low soil-test K levels. There were no significant corn yield increases with deep banding of K fertilizer relative to shallow placement in any tillage system. This study suggests that, for similar low-testing K soils, alternate K placements will have greater impacts on corn plant nutritional status than on final yields. Surface broadcasting of K fertilizer is appropriate for continuous NT corn despite evident K stratification present after long-term NT. MT may improve corn K nutrition after long-term NT. 相似文献
56.
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58.
安宁河流域免耕覆盖对稻田土壤性状及作物产量的影响研究 总被引:1,自引:0,他引:1
[目的]探索免耕覆盖在四川省西昌市主要轮作方式中的技术措施及其对土壤性状和作物产量的影响。[方法]2008年开始在西昌市小庙乡进行水稻-小麦轮作免耕覆盖的长期定位试验,共设置7个处理,选择其中有代表性的3个处理(①翻耕并将秸秆带离本田;③秸秆翻耕入土;⑤免耕秸秆覆盖还田)定期测定土壤养分含量、土壤含水量、土壤温度等,并对各处理水稻产量进行比较。[结果]处理⑤土壤有机质含量分别较处理①、③提高了6.81%和0.93%,土壤全氮含量分别较处理①、③提高了6.66%和2.67%,全磷和全钾含量分别较处理①提高了5.26%和8.34%;处理⑤土壤含水量较高,表土温度较低,水稻产量较高。[结论]免耕覆盖可提高土壤养分含量,调控土壤温度,增加土壤含水量,提高作物产量。 相似文献
59.
60.
Hiroyuki Tsuji Hiroyuki Yamamoto Kazuyuki Matsuo Kazuei Usuki 《Soil & Tillage Research》2006,89(2):167-176
A field experiment was conducted from 1983 to 1992 in Tsukuba, Japan to investigate the effects of tillage on soil conditions and crop growth in a light-colored Andosol. Three tillage methods (NT: no-tillage, RT: no-tillage for summer cropping and moldboard plowing for winter cropping, and CT: conventional rotary tillage to a depth of 15 cm) were employed in combination with crop residue application (+R, −R) and fused magnesium phosphate (FMP) fertilization (+P, −P). Under the combination of NT and +R, diurnal variation of soil temperature at a depth of 5 cm was smaller during the summer cropping season and soil temperature in the daytime was lower during the winter cropping season than under CT. Soil inorganic N concentration at a depth of 0–30 cm was +R > −R and NT > RT > CT. The early growth of summer crops was accelerated under NT in comparison with CT, and yields were higher under NT and RT in comparison with CT. On the other hand, winter crop yields were significantly reduced under NT, while they were still higher under RT in comparison with CT. Yields were higher with +R and +P application, respectively, and these effects were more pronounced in winter cropping. The positive effect of FMP fertilization was greater in combination with NT, and that of residue treatment was greater in combination with RT and NT than with CT. In conclusion, the best tillage practice for Andosols on the Kanto Plain is RT, i.e. a combination of NT for summer cropping and CT for winter cropping. The application of NT for winter cropping is not recommended, although the application of phosphate and crop residues could reduce the risk of yield reduction, because of improved soil nutrient status and moderation of diurnal soil temperature. 相似文献