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81.
为减少果园用工费,提高果园经济效益,在渭北旱塬以常规修剪苹果园为对照,监测量化修剪对疏花疏果用工费、果实品质和果园经济效益等的影响;在陕北丘陵沟壑区以苹果套袋(纸袋)为对照,监测喷施苹果面膜(腐殖酸型苹果免套袋膜剂)替代果实套袋对果园用工费、果实品质和果园经济效益等的影响。结果表明,量化修剪在冬季修剪时较常规修剪多支付用工费4500元/hm2,疏花可减少11250元/hm2,疏果可减少2250元/hm2;量化修剪的苹果单果重大,品质高,产值提高13.73%;经济效益提高34860元/hm2。喷施苹果面膜较果实套袋和去袋可减少用工费22850元/hm2,材料费减少8250元/hm2;喷施苹果面膜提高了苹果的外观商品价值和贮藏运输性能,产值提高50.01%;果园经济效益提高192900元/hm2。量化修剪和喷施苹果面膜降低了果园用工费,提高了果园经济效益,果园管理过程中应积极开展量化修剪和喷施苹果面膜。 相似文献
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The effects of two pruning regimes on the above-ground biomass allocation and nodulation of Gliricidia sepium (Jacq.) Walp.
(Leguminosae: Robinieae) were studied in a cut-and-carry forage production system under humid tropical conditions in Guadeloupe,
French Antilles. The grass layer composed of a mixture dominated by Paspalum notatum Flügge (80%) and Digitaria decumbens
Stent. The pruning regimes were partial pruning (ca. 50%) every two months and complete pruning every six months. The complete
pruning caused an almost complete turnover of N2 fixing nodules. The nodule biomass decreased after the partial pruning, but
the turnover was not complete. The nodule to foliage biomass ratio followed the same pattern under both treatments, and the
values of the ratio converged towards the end of the experimental period. The maxima of standing nodule biomass were 7.2 and
13.0 kg ha−1 in the partially and completely pruned trees, respectively. The cumulative leaf fodder harvest was higher under
partial pruning management, due to smaller litter loss. The branch biomass production was higher under complete pruning management.
Grass production was not affected by the pruning pattern of G. sepium. It was concluded that the partial pruning management
produces more fodder in the studied association, and the nodulation probably adjusts to the canopy N requirements. The potential
N release to soil in the turnover of nodules of G. sepium (max. 0.82 kg ha−1) is negligible compared to the N export in tree
and grass fodder harvest, 190 and 215 kg ha−1 in partially and completely pruned plots, respectively.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
84.
Effects of green pruning on growth and stem shape of Eucalyptus nitens (Deane and Maiden) Maiden 总被引:2,自引:0,他引:2
An experiment was established in two high quality Eucalyptus nitens Deane and Maiden (Maiden) plantations in Tasmania. At the start of the experiment the trees were three years old and the plantations were on the point of canopy closure. Selected trees were pruned to remove 0, 50% or 70% of the lower green crown length, and each was surrounded by eight unpruned trees. The 50% treatment had no impact on height or diameter increment in the two years following treatment, but removal of 70% of the lower crown length resulted in significant decreases in both height and diameter increment. There were no changes in the height of 50%-pruned trees relative to the height of surrounding unpruned trees (relative height), and it was concluded that dominance would not be affected by this treatment. The relative height of 70%-pruned trees was less at one site, and this treatment may result in loss of dominance. Stem taper was generally unaffected by either pruning treatment. Changes in stem form were restricted to trees in the 70% pruning treatment and were only transient. It was concluded that removal of 50% of the lower green crown length is an appropriate level of pruning for the species provided that growth rates are rapid and pruning is timed to coincide with canopy closure. Since dominance was unaffected by this level of pruning, thinning at the time of pruning is unnecessary. It may be possible to minimise the impact on growth of higher levels of pruning by thinning at the time of pruning. 相似文献
85.
Roots of 2-year-old black spruce seedlings (Picea mariana [Mill.] B.S.P.) were exposed to freezing temperatures to destroy 20, 40, 60, and 80% of the root systems. For comparison, other root systems were pruned to eliminate the same proportions of roots. Treated and control seedlings were planted in spring 1992 at Forêt Montmorency (the Université Laval forest research station, 50 km north of Quebec City). From 1992 to 1995, survival, shoot height and stem diameter were measured. Mortality mainly occurred in 1993, the year after planting; pruned seedlings showed practically no mortality while seedlings with 20, 40, 60, and 80% of their root systems affected by frost showed mortality rates of 0, 6, 17, and 24%, respectively. Shoot height and stem diameter decreased with increasing root damage when compared to controls. After three years on the planting site, shoot height was reduced by 2, 8, 11, and 18% while stem diameter was reduced by 4, 21, 25, and 24% for 20, 40, 60, and 80% frost damage, respectively. For pruned seedlings, shoot height was increased by 3% at 20% damage and was decreased by 1, 3, and 13% for 40, 60, and 80% root damage while stem diameter was reduced by 1, 4, 8, 19% for 20, 40, 60, and 80% respectively. Use of damaged seedlings on the planting sites should be limited in order to reduce the cost of replacement planting. 相似文献
86.
疏伐及修剪对油松无性系开花和树体的影响 总被引:7,自引:0,他引:7
在对兴城油松种子园的去劣疏伐、截顶和修剪基础上,就几种技术措施对无性系植株花量、枝条生长的影响和控制树高的有效性作了调查分析.去劣疏伐后第3年保留株的雌花量增长显著,枝均雌花量为对照的1.5~2.7倍,树冠下部枝条花量的增长较大;截顶、疏枝修剪均能显著提高雌球花量,对20龄左右植株的促花效果要好于10龄左右植株,且效果持续时间长;截顶+修剪处理对树冠上部枝条雌花量的促进作用高于对下层枝条;无论是去劣疏伐还是截顶修剪,其保留植株的雄球花量均低于对照;截去19龄植株顶端5年生主干能够控制株高,截去12龄植株顶端3年生主干后有“多头”和侧枝替代主干趋势,12龄植株在截顶后胸径生长有明显下降现象.对不同嫁接年龄无性系植株截顶疏枝的处理效果,疏伐和截顶疏枝对雌、雄球花影响的差异等问题作了探讨. 相似文献
87.
N. Z. Lupwayi I. Haque A. R. Saka D. E. K. A. Siaw 《Biology and Fertility of Soils》1999,28(2):196-203
The effects of Leucaena leucocephala and L. pallida prunings and cattle manure on maize nutrient uptake and yield were investigated in a hedgerow intercropping trial in the
Ethiopian highlands. Hedgerow intercropping (also called alley cropping) is an agroforestry system in which trees are grown
in dense hedges between alleys where short-cycle crops are grown. The hedges are pruned periodically during the cropping period
and the prunings are added to the soil as green manure. For each leucaena species, the experiment had 16 treatments resulting
from a factorial combination of four levels of leucaena leaf prunings (no prunings applied; first prunings applied; first
and second prunings applied; first, second and third prunings applied), two levels of air-dried cattle manure (0 and 3 t dry
matter ha–1) and two levels of N fertilizer (0 and 40 kg N ha–1 as urea). Uptake of N, P and K increased significantly with application of the three nutrient sources, but uptake of Ca and
Mg either did not respond or decreased with application of prunings and manure. All the three factors increased maize grain
and stover yields significantly, usually with no significant interactions between the factors. At least two applications of
prunings were required to significantly increase nutrient uptake and maize yield. Maize in the row closest to the hedge did
not respond to these nutrient inputs. It is concluded that hedgerow intercropping, with or without manure application, can
increase crop yields moderately (to 2–3 t ha–1 maize grain yields) in the highlands, but P, Ca and Mg may have to be supplied from external sources if they are deficient
in the soil. Additional N is still required for higher yields (>4 t ha–1 maize grain yields). However, quantification of the competition effects of the trees is also required to confirm these results.
Received: 27 January 1997 相似文献
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