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91.
The Nitrates Directive (91/676/EEC, Anonymous, 1991) was developed in Europe to limit environmental threats from intensive livestock farming and N fertilizer applications to crops. It imposed several rules on farmers and public bodies, one of which was nutrient fertilization plan adoption. Here we use results from the Tetto Frati (Northern Italy) Long-Term Experiment to verify the terms and coefficients in the official Italian guidelines and evaluate the limitations imposed to organic fertilization amounts. For this purpose, we mined long-term experimental data of crop yield, N uptake, N use efficiency, and soil organic matter content from miscellanea cropping systems fertilized with farmyard manure (FYM) and bovine slurry (SLU), typical of a dairy farm in Northern Italy. N fertilization efficiency indicators (Removal to Fertilizer ratio, Apparent Recovery and Nitrogen Fertilizer Replacement Value) indicated that in the long run, FYM behaved similarly to urea, and better than SLU. Even N supply rates as high as 250 kg N ha−1 were justified by high rates of crop removal. In fact, among the terms of the mass-balance equation, SOM mineralization was found to be most relevant, followed by meadow rotation residual effects. We conclude that a revised Nitrates Directives application scheme could be more relaxed in its application limit of manure-N, but should be more ambitious in setting efficiency coefficients for manure fertilization. 相似文献
92.
氮肥运筹对水稻产量及氮素利用率的影响 总被引:4,自引:0,他引:4
以北方超级稻沈农265为材料,研究了氮肥运筹对水稻产量形成及氮素利用率的影响.结果表明:施纯氮210kg/hm2,且基蘖肥与穗粒肥比为6∶4时,由于单位面积有效穗数较其他处理提高2.4%~21.1%,致使产量提高3.3%~20.2%;同一基蘖肥与穗粒肥施用比例下,随施氮量的增加,沈农265的总吸氮量呈上升趋势,而氮素利用率有下降趋势;不同施氮量条件下,穗粒肥比例增加有利于总吸氮量和氮素利用率的提高;适宜施氮量和基蘖肥与穗粒肥比例,能为水稻整个生育期提供比较平衡的氮素供应,提高氮肥利用效率,协调产量构成因素,从而提高产量,节本增效. 相似文献
93.
94.
Meng Yang Yongchun Li Scott X. Chang Tian Yue Weijun Fu 《Communications in Soil Science and Plant Analysis》2017,48(3):332-344
Impact of combined application of inorganic and organic fertilizers on soil carbon dioxide (CO2) emission is poorly understood. We investigated the effects of inorganic fertilizer (IF), organic fertilizer (OF), and a mixture of organic and inorganic fertilizers (OIF) applications on the dynamics of soil CO2 efflux in intensively managed Moso bamboo plantations. Soil CO2 efflux and concentrations of water soluble organic C (WSOC) and microbial biomass C (MBC) in the IF treatment were higher than those in the control but lower than those in the OF and OIF treatments. Both OF and OIF treatments increased the SOC stock. Strong exponential relationships (p < 0.01) between soil temperature and CO2 efflux were observed in all treatments. Soil CO2 efflux in all four treatments was correlated with WSOC (p < 0.05) but not with MBC. We concluded the combined approach can possibly contribute to increasing the level of SOC stock in intensively managed plantations. 相似文献
95.
采用配方施肥方案进行磷、钾肥效试验(3次重复,9个处理),研究磷钾肥配施对紫云英种子产量的影响,并筛选出适宜的磷、钾用量。结果表明,所有施肥处理的种子产量都高于不施磷钾肥即P0K0与P0K0相比,各施肥处理P1K2,P2K1,P1K1,P2K3,P2K2,P3K2,P2K0和P0K2留种产量分别提高了35.91%,35.37%,21.21%,20.79%,10.82%,10.20%,1.81%和1.47%。P1K2和P2K1这2个处理都显著或极显著高于P1K1,P2K3,P2K2,P3K2,P2K0,P0K2,P0K0。在性状特征方面(株高、茎粗、每分枝结荚花序数及结荚数),P2K3和P3K2相对优于其它施肥处理。可见,合理配施磷钾肥对提高紫云英种子产量有重要影响。 相似文献
96.
肥密水平对不同基因型冬小麦籽粒灌浆特性的影响 总被引:2,自引:0,他引:2
为确定施肥量和种植密度对不同品种小麦灌浆特性的影响, 采用多因素随机区组设计试验方法, 对优质冬小麦"陇鉴301"、"宁麦5号"和"1R17"的籽粒灌浆特性进行了研究, 应用Logistic方程对灌浆进程进行了拟合, 并就施肥量、种植密度和品种3因素进行了方差分析.结果表明:不同肥密水平下小麦灌浆进程符合Logistic生长曲线, 呈"慢-快-慢""S"型变化.肥密水平对3品种12项灌浆参数均产生影响, 但影响的具体参数和影响程度因品种而异.在高密度高肥处理下, "陇鉴301"、"宁麦5号"较为适应, 产量最高(4 188.09 kg·hm-2, 3 789.89 kg·hm-2);高密度中肥处理下, "1R17"最为适应, 产量最高(3 018.18 kg·hm-2), 且灌浆过程达到最佳状态.不同品种肥密互作效应达极显著水平, 具有正向的互作值.为提高小麦产量, 生产上应依据不同基因型品种的特性来确定施肥量和种植密度. 相似文献
97.
98.
Kimberly R. Love-Myers Alexander Clark III Laurence R. Schimleck Eric J. Jokela Richard F. Daniels 《Forest Ecology and Management》2009
Wood quality attributes were examined in six stands of slash pine (Pinus elliottii Engelm. var. elliottii) and loblolly pine (P. taeda L.) in the lower Coastal Plain of Georgia and Florida. Several plots comprised each stand, and each plot was divided so that it received three fertilizer treatments: a control treatment with herbaceous weed control at planting and brush control at mid-rotation only (control); 45 kg ha−1 N + 56 kg ha−1 P + herbaceous weed control at planting and 224 kg ha−1 N + 45 kg ha−1 P + brush control at mid-rotation (fertilizer with N at planting); and 56 kg ha−1 P + herbaceous weed control at planting and 224 kg ha−1 N + 45 kg ha−1 P + brush control at mid-rotation (fertilizer without N at planting). Ring width, ring earlywood specific gravity (SG), ring latewood SG, whole ring SG, and ring percent latewood were measured on each of seven trees. Of these measurements, this study focused mainly on the properties related to SG. Examination of the rings showed that latewood SG was significantly lower in trees treated with fertilizers with and without N at planting in the two to three years following fertilization, but that latewood SG gradually returned to a level similar to the control. Fertilizer without N at planting may also have had a brief negative effect on earlywood SG following mid-rotation fertilization, but it was not as clear or lasting as the effect on latewood SG. Additionally, although slash and loblolly pine appear to differ in the developmental patterns of these SG properties, there were no significant differences in how these patterns interacted with treatment. This study demonstrated that fertilization treatments have similar short-term effects on the SG of slash and loblolly pines, particularly in latewood, but the trees will return to a SG pattern consistent with unfertilized trees within two or three years. 相似文献
99.
100.