长期定位施肥对水稻、小麦产量和土壤养分的影响

经连续12年有机肥和化肥配施的定位试验,至第12年对水稻、小麦进行数据监测,结果表明,3个施化肥处理中,施栏肥配施化肥处理的有效穗比秸秆还田配施化肥作物（小麦、单季稻）2季增加86.9万/hm2,秸秆还田配施化肥的有效穗比单施化肥作物（小麦、单季稻）2季增加11.65万/hm2;作物（小麦、单季稻）产量2季以施栏肥配施化肥比秸秆还田配施化肥年平均增产367.5 kg/hm2,增长率为3.4%,秸秆还田配施化肥比单施化肥年增长率提高了5.8%。3个不施化肥处理中,施栏肥的有效穗比秸秆还田作物（小麦、单季稻）2季增加33.3万/hm2,秸秆还田的有效穗比不施肥（对照）作物（小麦、单季稻）2季增加19.95万/hm2。施栏肥比秸秆还田年平均增产277.5 kg/hm2,增长率7.4%,秸秆还田比不施肥（对照）增产15.8%。土壤养分施栏肥和秸秆还田耕层（0～20 cm）土壤有机质、全氮、全磷、碱解氮、速效磷均有提高,施栏肥增幅最大,无机区增幅较小。而全钾、速效钾含量变化程度不同。通过监测结果得出,以栏肥配施化肥的施肥方式对作物增产和改良土壤效果最好。     

长期秸秆还田对冬小麦产量及土壤肥力的影响

经连续12年4个不同施肥处理定位试验研究结果表明,单施秸秆比不施肥处理增加小麦基本苗37.0万株.hm-2,提高11.7%;增加有效穗14.0万穗.hm-2,提高6.3%,增加小麦产量161.1 kg.hm-2,提高13.7%。化肥+秸秆还田比单施化肥处理增加小麦基本苗15.0万株.hm-2,提高4.5%;增加有效穗14.2万穗.hm-2,提高3.9%;增加小麦产量196.9 kg.hm-2,提高6.2%。秸秆还田比单施化肥处理提高耕层(0~20 cm)土壤有机质含量5.6%~6.5%,同时提高土壤全氮、碱解氮、有效磷含量;单施化肥和化肥+秸秆还田能够提高土壤速效钾含量,而不施化肥和单施秸秆则使土壤速效钾含量呈下降趋势。因此,在秸秆还田中,要注意适当增加钾肥的施用量,以弥补作物高产大量携走土壤中的钾,保持土壤钾素平衡。     

旱地玉米秸秆还田对土壤肥力的影响

 研究探讨了玉米秸秆还田方式 (直接或过腹还田 )与化肥配施对土壤养分变化的影响。研究表明 ,秸秆过腹还田对提高耕层土壤速效 N贡献较大 ;耕层土壤速效 P含量主要与化肥施用量有关 ;耕层土壤速效 K含量与秸秆直接还田有关。该试验条件下 ,秸秆直接还田和秸秆过腹还田的土壤有机质含量基本保持平衡。产量统计分析表明 ,化肥对提高玉米产量及水分利用效率有明显影响 ,其次为秸秆直接翻压还田。适宜的秸秆直接还田量、秸秆过腹还田量与化肥 N配比 (试验中每公顷用量分别为 60 0 0、1 50 0和 1 0 5kg) ,其产量、水分利用效率和肥料 N的利用效率较高。研究为该区玉米秸秆作为饲源和有机肥源的合理再分配利用 ,秸秆、牛粪与化肥平衡配施 ,以及秸秆还田对土壤肥力的贡献和对作物产量的影响提供了依据。     

秸秆还田对作物产量和土壤肥力的短期效应

以水稻为试验材料,连续4 a年开展秸秆还田试验,研究前茬小麦秸秆还田对后茬水稻产量和土壤肥力的影响。结果表明,秸秆还田可增加后茬水稻产量,且水稻增产率随秸秆还田年限的增加而提高。连续实施秸秆还田3~4 a,土壤有机质水平显著高于对照,但秸秆还田对土壤全氮含量的短期效应尚未显现。与对照相比,秸秆还田提高了土壤有效磷和速效钾含量,且土壤有效磷和速效钾含量随着秸秆还田开展年限的增加而提高。秸秆还田降低了土壤容重、提高了土壤阳离子交换量,且秸秆还田年限越长,效果越明显。由此可见,秸秆还田是增加作物产量、提高土壤肥力的有效途径,秸秆还田对作物增产和耕地质量的提升效应随着实施年限的增加而越发突出。     

基于秸秆还田麦稻连作全年定位减量施肥试验的化肥减量增效研究

为了研究秸秆全部还田对减施化肥、增加经济效益的影响,开展了为期一年的麦-稻轮作秸秆全部还田化肥减量试验。试验设五个处理,分别是：秸秆不还田+常规施肥100%,秸秆还田＋常规施肥100%、90%、80%、70%。试验结果表明,秸秆还田区土壤容重下降,土壤有机质和全氮含量高于秸秆不还田区;随着秸秆还田次数的增加,土壤中缓效钾含量增加,有效磷含量下降;秸秆还田有助于提高粮食产量、减少化肥施用量、提高经济效益。配合作物秸秆资源化利用,调整施肥结构,水稻土麦-稻全年连作区种植作物,可以适度减少化肥用量(10%左右),对促进耕地质量提升,化肥减量增效具有一定的现实意义。     

粮田土壤培肥模式筛选试验

通过开展常规施肥、纯化肥施用、有机无机配施和秸秆粉碎还田结合化肥施用4种典型的粮田土壤管理技术模式对粮田土壤培肥的效果、作物产量的影响,筛选出最佳粮田培肥模式。试验结果表明:秸秆还田配施部分化肥玉米季较常规施肥能提高作物产量11.9%,小麦季提高14.44%,与纯化肥施用、有机无机配施两种技术模式相比产量略有提高或基本持平,但无显著差异。同时秸秆还田配施化肥处理还能提高土壤有机质和速效养分含量,玉米季和小麦季分别提升土壤有机质5.56%和9.60%。因此在京郊粮田土壤管理上推荐秸秆还田配施化肥的技术模式,并且在玉米秸秆还田填加秸秆腐熟剂。     

基于秸秆还田麦—稻连作全年定位减量施肥的效果研究

为了研究秸秆全部还田对减施化肥、增加经济效益的影响,开展了为期一年的麦—稻轮作秸秆全部还田化肥减量试验。结果表明,秸秆还田区土壤容重下降,土壤有机质和全氮含量高于秸秆不还田区;随着秸秆还田次数的增加,土壤中缓效钾含量增加,有效磷含量下降;秸秆还田有助于提高粮食产量、减少化肥施用量、提高经济效益。配合作物秸秆资源化利用,调整施肥结构,水稻土麦—稻全年连作区种植作物,可以适度减少化肥用量(20%左右),对促进耕地质量提升、化肥减量增效具有一定的现实意义。     

不同作物秸秆添加腐熟剂进行还田对水稻产量及土壤理化性质的影响

在肥西水稻主产区研究了不同秸秆添加腐熟剂进行还田对水稻产量及土壤理化性质的影响。结果表明:添加秸秆腐熟剂可以提高作物产量、增加土壤有机质及速效态养分含量、改善土体结构。秸秆添加腐熟剂进行还田可以相对减少化肥投入,提高经济效益及产投比。     

平塘县油菜秸秆腐熟还田化肥减量水稻试验效果研究

作物秸秆腐熟还田能增加土壤有机质含量,提高土壤供肥能力,进而减少化肥施用量。为了掌握我县油菜秸秆腐熟还田后油菜化肥常规用量的减少量和土壤理化性状,设置本试验。结果为:油菜秸秆腐熟还田后,水稻化肥常规用量减少5%增产极显著,可以减少至15%,但增产不显著。土壤有机质、全氮、碱解氮、有效磷、速效钾、缓效钾由有不同程度的提高,p H值都减少,说明土壤理化性状都在变化。     

不同耕作模式下秸秆还田对土壤理化性质的影响

通过连续两年定位试验,研究不同耕作模式下秸秆还田对土壤理化性质的影响。试验结果表明,秸秆还田能够改善土壤理化性质,提高土壤有机质、速效钾含量,但是对土壤全磷、速效磷影响较小。秸秆还田是影响土壤理化性质的主要因素,不同耕作模式之间差异不显著。     

头季稻与再生稻的品质比较研究

对20个水稻品种（组合）头季稻与再生稻的碾米品质、蒸煮品质、外观品质及营养品质进行了分析.结果表明,除精米粒形（长宽比）头季稻与再生稻无多大变化外,糙米率、垩白粒率、垩白度头季稻均高于再生稻,而糊化温度的碱消值则低于再生稻;头季稻与再生稻的精米率、整精米率、胶稠度、直链淀粉含量及蛋白质含量品种（组合）间存在明显差异,但大多数品种（组合）再生稻的精米率、整精米率比头季稻高,而直链淀粉和蛋白质含量则比头季稻低;总体评价是再生稻的米质比头季稻好.     

菊苣--饲料兼经济作物新秀

菊苣为菊科多年生草本植物,原产于欧洲,国外广泛用作饲料、蔬菜和制糖原料,80年代我国引进后又培育出大叶型品种,由于它品质优良,成为最有发展前途的饲料和经济作物新品种.     

Remote-sensing of crop yields

Our research efforts with durum wheat have led to the development of the SDD concept. Its application makes possible crop yield estimates from remotely acquired canopy temperatures and auxiliary air temperature measurements obtained during the period from head emergence to the cessation of head growth. Canopy albedo measurements appear adequate to delineate this critical period, making the technique potentially adaptable to predictions of crop yields by remote-sensing. The trifactor nomograms produced from combinations of the linear regression equations also suggest that the SDD concept may be used for scheduling irrigations by remote-sensing.     

转基因作物的安全性

目前人们对转基因作物的安全性评价焦点集中在释放的生态安全性、物种的遗传安全性和食物的消费安全性三个方面。对转基因作物安全性的检测目前还没有一套快速、准确、灵敏的方法,通常可用酶分析法和组织化学定位法鉴定标记基因,用PCR扩增法鉴定目的基因。     

Global crop forecasting

Many foreign countries are as dependent on imports of food as the United States is on imports of oil. As the world's largest exporter of food, the United States needs reliable information on fluctuating foreign crop production. But available information is often inadequate and at best untimely. It is gathered by the foreign governments' often outmoded systems and its release may be delayed out of economic self-interest. Recently three U.S. government agencies put together a crop inventory system using satellite remote sensing and worldwide weather reporting and tested it in the Large Area Crop Inventory Experiment (LACIE). A 1977 real-time forecast of U.S.S.R. wheat production indicates that the approach works and may be expandable to other areas and other crops.     

试论农作物种子包装设计

阐述了农作物种子包装的国际、国内概况和发展趋势,分析了我国农作物种子包装设计中的功能、色彩、图形等技术要素。提出了我国农作物种子包装行业在与国际接轨的同时,应充分发挥后发优势,走高起点、高效益、低成本、低消耗、无污染、可循环利用、由繁到简的知识产权自主的创新道路。     

Estimation of USLE crop and management factor values for crop rotation systems in China

Soil erosion on cropland is a major source of environmental problems in China ranging from the losses of a non-renewable resource and of nutrients at the source to contamination of downstream areas. Regional soil loss assessments using the Universal Soil Loss Equation(USLE) would supply a scientific basis for soil conservation planning. However, a lack of information on the cover and management(C) factor for cropland, one of the most important factors in the USLE, has limited accurate regional assessments in China due to the large number of crops grown and their complicated rotation systems. In this study, single crop soil loss ratios(SLRs) were collected and quantified for 10 primary crops from past studies or reports. The mean annual C values for 88 crop rotation systems in 12 cropping system regions were estimated based on the combined effects of single crop SLRs and the percentage of annual rainfall erosivity(R) during the corresponding periods for each system. The C values in different cropping system regions were compared and discussed. The results indicated that the SLRs of the 10 primary crops ranged from 0.15 to 0.74. The mean annual C value for all 88 crop rotation systems was 0.34, with a standard deviation of 0.12. The mean C values in the single, double and triple cropping zones were 0.37, 0.36 and 0.28, respectively, and the C value in the triple zone was significantly different from those in single and double zones. The C values of dryland crop systems exhibited significant differences in the single and triple cropping system regions but the differences in the double regions were not significant. This study is the first report of the C values of crop rotation systems in China at the national scale. It will provide necessary and practical parameters for accurately assessing regional soil losses from cropland to guide soil conservation plans and to optimize crop rotation systems.     

Physicochemical properties of chernozem and crop productivity in primary tillage systems in crop rotation

It is shown that, in a nine-course grain-sugar beet crop rotation, a combined tillage system (non-moldboard for cereals and moldboard for row crops)with annual application of 5 tons of manure and N₅₃P₅₆K₅₃ per hectare of rotation area restrains deterioration of the physicochemical properties of chernozem. The yield of all crops in the rotation increases.