桃树养分管理研究进展与展望

从桃树营养需求规律、大中微量元素施肥与桃树生长和抗逆性的关系、适宜桃树施用的肥料和桃树的营养状况诊断等方面,简要综述了国内外近年来的研究现状和进展情况,分析了中国桃树营养管理中存在的主要问题,对今后桃树营养的研究方向和管理策略进行了初步探讨与展望.     

Integrated management of irrigation water and fertilizers for wheat crop using field experiments and simulation modeling

The reported study aimed at developing an integrated management strategy for irrigation water and fertilizers in case of wheat crop in a sub-tropical sub-humid region. Field experiments were conducted on wheat crop (cultivar Sonalika) during the years 2002–2003, 2003–2004 and 2004–2005. Each experiment included four fertilizer treatments and three irrigation treatments during the wheat growth period. During the experiment, the irrigation treatments considered were I₁ = 10% maximum allowable depletion (MAD) of available soil water (ASW); I₂ = 40% MAD of ASW; I₃ = 60% MAD of ASW. The fertilizer treatments considered in the experiments were F₁ = control treatment with N:P₂O₅:K₂O as 0:0:0 kg ha⁻¹, F₂ = fertilizer application of N:P₂O₅:K₂O as 80:40:40 kg ha⁻¹; F₃ = fertilizer application of N:P₂O₅:K₂O as 120:60:60 kg ha⁻¹ and F₄ = fertilizer application of N:P₂O₅:K₂O as 160:80:80 kg ha⁻¹. In this study CERES-wheat crop growth model of the DSSAT v4.0 was used to simulate the growth, development and yield of wheat crop using soil, daily weather and management inputs, to aid farmers and decision makers in developing strategies for effective management of inputs. The results of the investigation revealed that magnitudes of grain yield, straw yield and maximum LAI of wheat crop were higher in low volume high frequency irrigation (I₁) than the high volume low frequency irrigation (I₃). The grain yield, straw yield and maximum LAI increased with increase in fertilization rate for the wheat crop. The results also revealed that increase in level of fertilization increased water use efficiency (WUE) considerably. However, WUE of the I₂ irrigation schedule was comparatively higher than the I₁ and I₃ irrigation schedules due to higher grain yield per unit use of water. Therefore, irrigation schedule with 40% maximum allowable depletion of available soil water (I₂) could safely be maintained during the non-critical stages to save water without sacrificing the crop yield. Increase in level of fertilization increases the WUE but it will cause environmental problem beyond certain limit. The calibrated CERES-wheat model could predict the grain yield, straw yield and maximum LAI of wheat crop with considerable accuracy and therefore can be recommended for decision-making in similar regions.     

保护地CO2施肥研究进展

对保护地内ＣＯ的变化规律,ＣＯ２施肥的效果,增产的原因,施肥时间等的研究结果,进行了综述,并介绍了ＣＯ２的施用方法、影响施肥效果的因素及注意事项。     

钾肥不同施用期对食用甘薯产量和品质的影响

为了探明适宜的钾肥施用量与施肥时期在提高甘薯产量和品质的同时,实现钾肥的高效利用和优化管理。以优质食用型甘薯徐薯32为试验材料,研究3个钾肥用量（0,150,300 kg／hm2）和3个施钾时期（生长早期即栽插后2周内、封垄期和块根膨大初期）处理对甘薯产量及营养成分的影响。结果表明：生长早期施用钾肥300 kg／hm2时,块根鲜薯和薯干产量获得最高值,分别为36495．0,12175．5 kg／hm2。钾肥不同施用期和施用水平对所测甘薯品质性状影响较大,甘薯生长早期追施钾肥有利于淀粉、麦芽糖和蔗糖的积累;低钾处理有利于淀粉及糖类物质的积累,而高钾处理则有利于蛋白质的积累。     

施肥模式对日光温室土壤铵态氮和硝态氮的影响

通过种植两茬油菜,设置7种施肥模式:有机肥施氮量600 kg/hm2;有机肥施氮量300 kg/hm2;无机肥施氮量767 kg/hm2;无机肥施氮量383 kg/hm2;有机肥施氮量450 kg/hm2,无机肥施氮量153 kg/hm2;有机肥施氮量300 kg/hm2,无机肥施氮量383 kg/hm2;有机肥施氮量150 kg/hm2,无机肥施氮量191 kg/hm2,研究了日光温室0～200 cm土壤中NH4+-N和NO3--N的迁移累积。结果表明,不同施肥模式主要影响0～40 cm土壤中NH4+-N的平均累积量和平均质量比,单施无机肥的相应值大于单施有机肥;不同施肥模式主要影响0～40 cm土壤中NO3--N的平均累积量和平均质量比,当施氮量小于383 kg/hm2时,相应值从大到小依次为:单施无机肥、单施有机肥、有机肥和无机肥配施,不同施肥模式也影响40～160 cm土壤中NO3--N的迁移累积。从地下水污染风险和产量考虑,北京农业种植区日光温室油菜种植可按照有机肥150 kg/hm2、无机肥191 kg/hm2的施肥模式进行施肥。     

Influence of long-term fertilization with farmyard manure on soil organic matter: Characteristics of particle-size fractions

Summary The influence of more than 100 years of fertilization with farmyard manure on soil organic matter in comparison to unfertilized soil was studied in particle-size fractions using elemental (C and N) analyses and pyrolysis-field ionization mass spectrometry. Distinct differences in C and N concentrations and distribution and in the quality of organic matter between the size fractions and the fertilization treatments were observed. Clay-associated C and N were relatively higher in the unfertilized treatment, whereas the application of farmyard manure preferentially increased soil organic matter associated with the fine and medium silt fractions. Pyrolysis-field ionization mass spectrometry of soil fractions <20 m showed increasing values for lignin monomers and dimers and fatty acids with larger equivalent diameters, whereas the proportion of N compounds, mono- and polysaccharides and phenolics decreased in the larger size fractions. Sand fractions were particularly rich in lignin fragments, mono- and polysaccharides, and alkanes/alkenes. These relationships seemed to be independent of management practices. In the same size fractions of the different treatments, however, a higher relative abundance of N-compounds, mono- and polysaccharides, phenolics, lignin monomers, and alkanes/alkenes was observed in the unfertilized variant. Lignin dimers and fatty acids were more abundant in the farmyard manure treatment. Both trends together imply that soil enrichment in organic matter due to the application of farmyard manure largely reflects an increase in lignin building blocks and partly reflects an increase in lipids such as fatty acids in the silt fractions. Therefore these constituents are of particular importance in assessing the positive effects of farmyard manure on soil fertility.     

尿素施肥量对土壤微生物和酶活性的影响

不同肥料用量对土壤生物学过程的影响研究是肥域(际)土壤生态学研究的重要内容之一。本试验采用室内模拟培养试验,研究了不同尿素施肥量对潮土微生物数量和酶活性的影响。结果表明:放线菌和霉菌对尿素施肥量比较敏感,B(肥土比1:1500)施肥量就可以明显降低它们的数量,分别比不施肥(A)下降45.5%和32.2%。硝化细菌在D(肥土比1:400)施肥量时数量最大,之后随施肥量增加而下降,反硝化细菌随施肥量增加直线下降。土壤酶活性均在E(肥土比1:200)施肥量时发生明显变化,脲酶、中性磷酸酶和蔗糖酶活性急剧下降。     

施肥模型研究综述

对施肥模型和参数研究的历史、现状和趋势进行了综述,并指出今后定量施肥研究的关键问题。     

Influence of management practices on soil organic matter changes in the Northern China plain and Northeastern China

Soil organic matter (SOM) is strongly related to soil type and management practices. Changes in government policy have brought drastic changes in farm management practices in the last two decades in rural China. This study investigates changes in SOM in two different soils: Ustepts and Udolls. Ustepts, in the North China Plain where the climate is warm and sub-humid, developed from an alluvial flood plain with organic matter <10 g kg⁻¹. Udolls, in Northeastern China where the climate is cool and sub-humid, developed from loess-like materials with organic matter >20 g kg⁻¹. Two locations for Ustepts and three locations for Udolls were used to collect 567 soil samples in 1980–1982 and again in 2000 for SOM analysis. Soil organic matter increased for Ustepts and decreased for Udolls soils over the sampling period, resulting from differences in fertilizer rates and crop residue input to soil. Higher fertilizer input and crop intensity and initially very low SOM content in Ustepts all contributed to greater OM input than oxidation release. In contrast, lower fertilizer input and crop intensity, and initially high SOM content in the Udolls, led to lower OM input than oxidation release. Increasing SOM content through higher mineral fertilizer input is a valuable option for sustainable agriculture production in areas where SOM is low and there is a shortage or potential shortage of food supply.     

施肥对日光温室土壤微生物与酶活性变化的影响

在日光温室内,采用田间试验的方法,研究不同施肥处理对西红柿土壤酶活性和土壤微生物数量的影响。结果表明:施有机肥、化肥、有机肥 叶面肥处理土壤磷酸酶活性增加,施化肥 叶面肥处理比施化肥处理土壤磷酸酶活性增加;施有机肥处理土壤脲酶活性增强;施化肥 叶面肥处理土壤磷酸酶活性比施有机肥 叶面肥处理降低;施肥对蔗糖酶和过氧化氢酶活性的影响较小。施有机肥处理土壤细菌、真菌和放线菌数量增加,施化肥处理土壤细菌数量降低,土壤真菌和放线菌数量增加。