黄土高原旱地不同施肥对土壤肥力与产量的影响

Long-term fertility experiments have become an important tool for investigating the sustainability of cropping systems. Therefore, a long-term (18-year) fertilization experiment was conducted in Changwu County, Shaanxi Province, China, to ascertain the effect of the long-term application of chemical fertilizers and manure on wheat yield and soil fertility in the Loess Plateau, so as to provide a scientific basis for sustainable land management. The experiment consisted of nine fertilizer treatments with three replicates arranged in a completely randomized design: 1) CK (no fertilizer); 2) N (N 120 kg ha-1); 3) P (P 26.2 kg ha-1); 4) NP (N 120, P 26.2 kg ha-1-2); 5) M (manure 75 t ha-1); 6) NM (N 120 kg ha-1, manure 75 t ha-1); 7) PM (P 26.2 kg ha-1, manure 75 t ha-1); 8) NPM (N 120 , P 26.2 kg ha-1, manure 75 t ha-1); and 9) fallow (no fertilizer, no crop). N fertilizer was applied in the form of urea and P was applied as calcium super phosphate. The results showed that precipitation had a large effect on the response of wheat yield to fertilization. Manure (M), NP, PM, NM, and NPM treatments significantly increased (P < 0.05) average yield. In the NP, PM, NM and NPM treatments, the percentage increases in yield due to fertilization were highest in normal years, and lowest in the drought years. Long-term P application enhanced soil available P markedly, and manure applications contributed more to soil fertility than chemical fertilizers alone. Chemical fertilizers applied together with manure distinctly improved soil fertility. The results also showed that the soil nutrient concentration changed mainly in the 0--60 cm layers and fertilization and planting only slightly affected soil nutrients below the 100 cm layers.     

耕作、残茬及施肥管理对土壤有机质动态变化影响的情景分析

Based on data from 10-year field experiments on residue/fertilizer management in the dryland farming region of northern China, Century model was used to simulate the site-specific ecosystem dynamics through adjustment of the model＇s parameters, and the applicability of the model to propose soil organic carbon （SOC） management temporally and spatially, in cases such as of tillage/residue/fertilization management options, was identified v/a scenario analysis.Results between simulations and actual measurements were in close agreement when appropriate applications of stover,manure and inorganic fertilizer were combined. Simulations of extreme C/N ratios with added organic materials tended to underestimate the measured effects. Scenarios of changed tillage methods, residue practices and fertilization options showed potential to maintain and enhance SOC in the long run, while increasing inorganic N slowed down the SOC turnover rate but did not create a net C sink without any organic C input. The Century model simulation showed a good relationship between annual C inputs to the soil and the rate of C sequestration in the top 20 cm layer and provided quantitative estimations of changes in parameters crucial for sustainable land use and management. Conservation tillage practices for sustainable land use should be integrated with residue management and appreciable organic and inorganic fertilizer application, adapted according to the local residue resource, soil fertility and production conditions. At least 50% residue return into the soil was needed annually for maintenance of SOC balance, and manure amendment was important for enhancement of SOC in small crop-livestock systems in which crop residue land application was limited.     

坡耕地增产措施试验研究

坡耕地增产措施试验研究李新会（河南省宜阳县水利局，４７１６００）一、试验区概况试验区位于河南省宜阳县董王庄乡恒庄村，属风化片麻岩丘陵区，土壤多为砂壤土和白灰土，地处暖温带季风气候区。年平均气温为１４．４℃，≥１０℃累计积温为４６１７．９℃，年日照时数...     

干旱缺水地区森林植被蒸散耗水研究

 系统总结近年来在宁夏固原六盘山、北京延庆等干旱缺水地区进行的森林植被蒸散耗水研究结果。乔、灌、草作为土壤水分限制型生态系统的坡面植被,蒸散都是水分平衡的最大分项,其中植被蒸腾又是蒸散的最大分项。植被蒸散量一般表现为高大乔木林>亚乔木林>灌木林>自然草地,但人工草地>自然草地。可依坡面产水功能将不同植被分类,自然草地和灌丛为水源生产型,亚乔木林为水源平衡型,高大乔木林和人工草地为水源消耗型。植株密度不是坡面植被蒸散大小的决定性因子,其作用更多的是调控蒸腾量及其占蒸散比例。虽然降低植株密度一般会减小蒸散,但并不是相同比例地线性下降,不同植被类型反应也不一样,表现出降低密度减少蒸散的作用从乔木、亚乔木到灌木而变弱的趋势,降低密度减少蒸散的作用是有限的。对降低密度减少蒸散的作用大小,作为调控措施的有效性,有效的密度调控范围等,还需严格的对比实验和理论研究。估计和评价植被蒸散耗水时,用叶面积指数或叶生长量指标可能比密度更符合生物学逻辑。从在干旱缺水地区建立节水、稳定、高效、多功能的坡面植被的角度而言,草地和灌丛的蒸散低于乔木林,建立稀树草原或稀树灌丛式的植被可能更利于流域产水和植被稳定。从小流域管理的角度而言,还需考虑在土壤水分承载力空间差异的基础上,探讨能兼顾产水功能、水土保持、水源涵养、植被稳定的植被空间优化配置的理论和技术。     

山西旱地小麦栽培技术体系的形成及其发展战略

系统论述了山西旱地小麦在山西小麦生产中的地位、现状及其与降雨的相关性，回顾了山西旱地小麦栽培技术体系的形成与发展，提出了山西旱地小麦再上新台阶的5项战略性意见。     

塿土旱作区施肥对小麦产量和水分利用效率的影响

研究了黄土高原南部塿土旱作区施肥对小麦产量和水分利用效率的影响。结量表明,合理增施肥料能显著提高冬小麦产量和水分利用效率,最高施肥量分别提高了1611kg/hm~2和0.235kg/mm水分。施肥量增加使小麦叶片水势有所降低,0～200cm土层贮水量呈发育前期升高而后期下降的趋势,改善了小麦植株自身调节和保持水分的能力,提高了产量和水分利用效率。     

黄土高原旱地春谷吸肥与土壤供肥规律研究

１９９０～１９９２年在山西榆次市对黄土高原旱地春谷吸肥与土壤耕层供肥规律进行了研究。结果表明，土壤耕层氮磷供给能力动态变化遵循倒Ｌｏｇｉｓｔ１０生长曲线方程变化，钾的供给能力动态变化遵循一次方程变化；谷子不同生育时期吸收氮磷钾动态变化遵循Ｌｏｇｉｓｔ１０生长曲线方程变化；谷子一生随着生育进程对氮磷钾的吸收量逐渐增加，土壤氮磷钾供给量则随着谷子吸收量的增加而减少，即供给能力趋于减弱，氮的吸收高峰与土壤供给高峰基本一致，磷的吸收高峰在土壤供给高峰之后，钾的吸收高峰在土壤第一供给高峰期，孕穗至抽穗阶段是谷子吸收氮磷钾的高峰期；从谷子一生来看，吸收氮磷量小于土壤供给量，钾的吸收量大于土壤供给量。通过分析并对榆次市黄土高原区旱地春谷施肥问题提出新见解，即亩产要达到２００ｋｇ以上应重视施用钾肥。     

陕西渭北旱源地区葡萄节水施肥与栽培技术研究

介绍了在海拔700～1000m高度且无灌溉条件的陕西渭北旱塬地区葡萄的节水施肥和"V"形架栽培技术,并将其与水肥条件良好的平原地区做了比较。结果表明:在陕西渭北旱塬地区使用黑地膜覆盖技术和施肥枪施肥技术,不但节约水肥,而且经济效益显著,值得推广应用。     

不同地膜周年覆盖对冬小麦土壤水分及利用效率的影响

为了探明不同地膜覆盖对早地冬小麦土壤水分及其利用效率的影响,选用普通地膜、生物降解膜以及液体地膜在陕西渭北旱塬旱作农田进行周年覆盖集雨栽培定位试验,研究了不同地膜周年覆盖对冬小麦不同生育时期土壤水分总贮量和不同土壤深度水分动态变化及其利用效率的影响.结果表明、周年覆盖地膜可提高土壤含水量,有利于土壤水库的扩蓄增容,并且...     

沼液对地膜小麦根系及产量影响研究

沼液浸种的地膜小麦具有合理的产量结构，比地膜小麦增产9.88%，比露地小麦增产67.65%，苗期着重促进了根系的发育，中后期更快地促进了地上部的生长发育，使植株的抗逆性增强。喷施叶面肥均表现为增产，其中KH₂PO₄效果最好，增产幅度11.94%～13.92%，其余依次为麦丰乐、沼液、红苹果2号，增产幅度不足6%，同时提高了株高、成穗数、穗粒数和粒重。