大蒜秸秆还田对稻田土壤培肥和杂交水稻产量的影响

在大蒜—水稻轮作模式典型区,以大蒜秸秆为研究对象,研究无秸秆还田（CK）、秸秆1倍焚烧还田（A1）、秸秆2倍焚烧还田（A2）、秸秆1倍翻压还田（B1）、秸秆2倍翻压还田（B2）、秸秆3倍翻压还田（B3）对土壤培肥和杂交水稻产量的影响。结果表明,在水稻分蘖期,秸秆还田处理的土壤有机质含量都显著高于CK;在水稻分蘖期、拔节期、抽穗期,秸秆还田处理的土壤碱解氮、速效钾含量都显著高于CK;秸秆还田比CK增产,其中秸秆翻压还田各处理增产显著,秸秆3倍翻压还田（B3）增产效果最好,比对照增产18.84%;秸秆翻压还田培肥效果较好,尤其在拔节期土壤碱解氮含量显著增加,导致其茎鞘物质输出率、茎鞘物质转换率较高,从而显著增产。     

基于秸秆还田条件下辽北地区适宜耕作方式及施肥量研究

通过两年田间小区试验,在秸秆还田条件下,设不同耕作方式(旋耕、翻压和免耕)和还田周期(连年和隔年),研究不同秸秆还田模式和施肥量对土壤理化性质和玉米产量的影响。结果表明,与常规种植不还田相比,翻压还田处理显著降低耕层土壤容重,免耕还田处理显著增加耕层土壤含水率,秸秆还田提高土壤有机质、氮、磷、钾养分含量。连年翻压还田处理玉米穗部性状最优,子粒产量最高;其次为免耕还田处理,旋耕还田处理不利于玉米产量的提高。在同等氮肥施用水平下,秸秆还田处理使玉米产量显著提高,在此基础上增加氮肥投入量并未带来显著增产效应。相同秸秆还田条件下,减施50%钾肥处理的玉米子粒产量无显著变化。在辽北地区,秸秆还田配合翻压、免耕耕作措施能够改善土壤理化形状,有利于玉米稳产高产,连年翻压还田对玉米增产效应最理想,且秸秆还田配合适宜的化肥减量措施不仅能保证作物产量,可降低养分流失污染环境的风险。     

棉田绿肥6625箭舌豌豆研究

我省关中棉区土壤有机质含量较低,影响棉花产量的提高。为了培肥地力,解决棉田肥料短缺,于1978、1979、1980和1983年进行了棉田间套春、夏绿肥品种和翻压期试验,又于1979～1984年进行了绿肥盆栽定位肥效测定,探讨绿肥翻压后土壤有机质和全     

3种南方绿肥腐解特征及其对淹水土壤养分和酶活性的影响

利用尼龙网袋法,盆栽模拟淹水土壤环境,研究南方常见绿肥紫云英、油菜和肥田萝卜的氮磷释放规律及其对淹水土壤酶活性的影响,绿肥翻压鲜重量为1.14 kg/m~2。在97 d的试验周期内,绿肥腐解率表现为:肥田萝卜紫云英油菜。3种绿肥向土壤环境中释放氮速率由高到低为:肥田萝卜油菜紫云英,并促进了总氮由土壤→溶液的释放,且土壤溶液97 d氮的平均增加量达到显著水平(p0.05)。磷的释放为:肥田萝卜紫云英油菜,其97 d土壤磷的平均增加量达到显著水平(p0.05);绿肥翻压显著影响了土壤多酚氧化酶和转化酶活性(p0.05)。同一种土壤酶在不同处理之间及同一处理条件下的不同酶之间均表现出显著的相关性(p0.05),即土壤酶在促进物质转化中不仅显示其专性催化特性,同时也体现了共性关系。3种绿肥中肥田萝卜改善土壤酶活性作用最明显。     

油菜作绿肥还田的培肥效应及对水稻生长的影响

 为明确油菜作绿肥对稻田土壤的培肥效应及其对后季水稻生长的影响,2004-2008年在浙江富阳进行空闲 单季稻（CK）、紫云英 单季稻(T1)、油菜收获后秸秆焚烧还田（T2）和油菜盛花期还田（T3）4种模式的定位试验。研究结果表明,油菜盛花期还田（T3）能提高土壤有机质、全氮和全磷含量,培肥地力;增加稻田土壤的总孔隙度,减少容重,改善土壤物理性状;增加后季水稻生长过程中土壤的脲酶和酸性磷酸酶活性,从而提高供试水稻品种的产量,其中杂交稻内2优6号、两优培九、秀优5号表现为有效穗数增多,常规稻秀水09的每穗粒数增加;在光合生理指标上,油菜作绿肥还田后,水稻的叶面积指数、剑叶叶长、叶宽、叶绿素含量、光合速率、干物质积累量增加。研究结果还表明,油菜作绿肥还田是一种很好的稻田生物培肥新途径,能以远低于紫云英的生产成本取得类似的水稻增产效果。     

旱区土壤无机氮素与春玉米根系时空分布对控释尿素输入的响应

以先玉698为供试材料,在等氮量(225 kg/hm²)条件下,以不施氮为对照(CK),设置UR (100%普通尿素,2/3基施,1/3小喇叭口期追施)、CRU1(1/3控释尿素+1/3普通尿素基施,1/3普通尿素小喇叭口期追施),CRU2(2/3控释尿素+1/3普通尿素一次基施)、CRU3(100%控释尿素基施)4种施氮模式,探究控释尿素输入对土壤氮素、玉米根系特性、氮素吸收及产量的影响。结果表明,相对于UR处理,CRU处理显著提升了春玉米生育中后期土壤硝态氮和铵态氮的含量,其中CRU2效果最明显。UR和CRU处理在不同时期对根系参数的影响不同,前期UR处理有利于根系的生长,花后CRU处理对0～80 cm土层根系长度及0～20 cm根重密度影响更大。通径分析进一步表明,玉米根长及根重密度的变化是增产的重要原因之一。CRU处理显著提升了玉米整个生育期内植株氮素含量及最终子粒产量。花后15 d,CRU处理较UR提高了子粒氮素含量,CRU处理间以CRU2最佳。CRU2处理子粒产量为14.65 t/hm²,分别较CK、UR、CRU1、CRU3提高32.70%、5.78%、1.52%、5.17%。在宁南山区CRU2处理能实现春玉米高产高效。     

缓释尿素在玉米上的应用效果

利用大田小区试验,在赤峰市和鄂尔多斯市分别进行不同氮素处理对玉米产量、肥料吸收利用和土壤氮残留影响的研究。结果表明,施用氮肥玉米子粒产量和秸秆产量可分别增加13.3%～157.2%和6.9%～64.2%。减少20%施氮量同时配比75%的缓释尿素处理,玉米子粒氮含量、秸秆氮含量和氮积累量最大,与100%推荐施氮量无显著差异。缓释尿素占比60%以上时氮素回收率、氮肥偏生产力和氮肥农学效率达最大值,较普通尿素(RU)可分别提高14.3、4.5、61.7个百分点(赤峰市)和8.4、11.0、35.7个百分点(鄂尔多斯市)。玉米收获后耕层(0～20 cm)土壤矿质氮含量表现,赤峰市耕层土壤硝态氮含量远大于铵态氮且不同处理间差异显著(P0.05),100%推荐施氮量最大,80%推荐施氮量(RU80%)最小。鄂尔多斯市耕层土壤硝态氮含量和铵态氮含量基本相当,除各氮素处理与对照(CK)达显著差异外(P0.05),其他各处理间均未达显著差异。施氮量减少20%,缓释尿素占比30%以上与普通尿素配施即可替代100%推荐施氮量,且缓释尿素占比越大养分吸收利用越显著,玉米产量间无显著差异。     

吉林省黑土区玉米氮肥减施效果研究

针对目前吉林省黑土区玉米种植过程中氮肥用量偏高导致的氮肥利用率低、氮素残留高等问题,在习惯施氮量的基础上设降低10%、20%、30%、40%的不同氮肥减量处理,研究减氮对春玉米干物质积累、子粒产量、氮素利用效率及土壤中无机氮积累的影响。结果表明,伏龙泉和米沙子试验点降低20%氮肥用量、开安试验点降低30%氮肥用量玉米子粒产量无显著降低,减氮处理显著提高氮肥的利用效率。降低氮肥用量可减少玉米收获后耕层土壤中无机氮的积累(硝态氮)。玉米施氮量在223 kg/hm2时玉米收获后耕层土壤无机氮含量与播种前基本一致。吉林省黑土玉米种植区适当降低氮肥用量不会显著影响玉米产量,同时会提高氮肥利用效率,减少玉米收获后耕层无机氮的积累。     

不同绿肥翻压还土后植烟土壤主要养分动态变化

为探索不同绿肥翻压还土对土壤养分的影响,采用大田试验研究了光叶紫花苕、箭舌豌豆、紫云英、普通黑麦草、冬牧70、满园花等6种绿肥翻压后土壤主要养分含量的动态变化。结果表明:(1)绿肥翻压还土能够提高土壤有机质、碱解氮、有效磷和速效钾含量,分别为2.64%~13.33%、19.25%~40.99%、2.32%~18.75%、47.94%~76.50%;(2)不同绿肥品种以普通黑麦草提高土壤有机质幅度最大,以箭舌豌豆提高土壤碱解氮和有效磷幅度最大,以紫云英提高土壤速效钾幅度最大;(3)不同绿肥种类以禾本科绿肥提高土壤有机质的效果较好,以豆科绿肥提高土壤碱解氮、有效磷和速效钾的效果最好。     

增施有机肥对夏玉米物质生产及土壤特性的影响

2015和2016年在大田试验条件下,研究不施肥(CK)、常规施肥(NPK)、常规施肥+有机肥(增施鸡粪1 500 kg/hm~2,NPKM)对夏玉米物质生产及土壤特性的影响。结果表明,与CK相比,NPK和NPKM处理2015和2016年玉米产量分别增加13.62%和18.61%、36.75%和44.93%。植株叶片SPAD值、植株根系和地上部生物量均表现为NPKMNPKCK。与CK相比,增施有机肥后,土壤呼吸、硝态氮、铵态氮含量、脲酶、蔗糖酶活性均显著增高,过氧化氢酶活性降低。相关分析表明,连续两年玉米子粒产量均与拔节期、吐丝期、成熟期的SPAD值和硝态氮含量呈显著正相关,与吐丝期和成熟期的根系生物量、地上部生物量、蔗糖酶活性呈显著正相关。     

Management of Soil Micronutrient Deficiencies in the Rice-Wheat Cropping System

Summary

Within the last three decades, the rice-wheat cropping system has triggered, and with time, aggravated soil micronutrient deficiencies in the Indo-Gangetic Plains (IGP). This has largely been due to the shift from an earlier rice and wheat monoculture with low yielding, long duration indigenous varieties, to an intensive rice-wheat rotation cropping system with short duration modern high yielding varieties on the same piece of land. The problems related to micronutrient deficiency in the IGP are more due to the size of its available pools in the soil rather than its total contents and are greatly influenced by crop management, or rather its mismanagement. Deficiency of zinc is widespread in the IGP, but with the extensive use of zinc sulfate, zinc deficiency has reduced in some areas of the region. Meanwhile, the deficiency of Fe, Mn and B has increased in the IGP. Deficiency of Cu and Mo is location specific and can limit rice and wheat yields. The adoption and spread of the rice-wheat system in permeable coarse textured soils, particularly in the western IGP, not only caused iron deficiency in rice but also resulted in the emergence of manganese deficiency in wheat. In highly calcareous and acidic soils, boron is the next limiting micronutrient in crop production after zinc. Bumper rice and wheat harvests in the past decade, the declining use of organic manures in the region and except for the widespread use of zinc sulfate, a general lack of awareness amongst farmers on micronutrient deficiency problems has contributed to micronutrients limiting rice and wheat yields in the IGP. Approaches to alleviating micronutrient deficiencies include matching the crop removals of the micronutrients with its replenishments through their respective external carriers, supplementation through organic sources and mobilization/utilization through cultivation of micronutrient efficient crop cultivars. Identification of efficient micronutrient carriers and finding the optimum rate, mode and time of its application is important in ameliorating the micronutrient deficiencies. This article reviews the extent of micronutrient deficiency and discusses various management options available to reduce micronutrient deficiency induced crop yield reduction for rice and wheat in the Indo-Gangetic Plains.     

Enhancing the mineral and vitamin content of wheat and maize through plant breeding

More than half of the world's population suffers micronutrient undernourishment. The main sources of vitamins and minerals (iron, zinc, and vitamin A) for low-income rural and urban populations are staple foods of plant origin that often contain low levels or low bioavailability of these micronutrients. Biofortification aims to develop micronutrient-enhanced crop varieties through conventional plant breeding. HarvestPlus, the CGIAR's biofortification initiative, seeks to breed and disseminate crop varieties with enhanced micronutrient content that can improve the nutrition of the “hard to reach” (by fortification or supplementation programmes) rural and urban poor in targeted countries/regions. In attempting to enhance micronutrient levels in maize and wheat through conventional plant breeding, it is important to identify genetic resources with high levels of the targeted micronutrients, to consider the heritability of the targeted traits, to explore the availability of high throughput screening tools and to gain a better understanding of genotype by environment interactions. Biofortified maize and wheat varieties must have the trait combinations which encourage adoption such as high yield potential, disease resistance, and consumer acceptability. When defining breeding strategies and targeting micronutrient levels, researchers need to consider the desired micronutrient increases, food intake and retention and bioavailability as they relate to food processing, anti-nutritional factors and promoters. Finally, ex ante studies are required to quantify the burden of micronutrient deficiency and the potential of biofortification to achieve a significant improvement in human micronutrient status in the deficient target population in order to determine whether a biofortification program is cost-effective.     

Enhancing the mineral and vitamin content of wheat and maize through plant breeding

More than half of the world's population suffers micronutrient undernourishment. The main sources of vitamins and minerals (iron, zinc, and vitamin A) for low-income rural and urban populations are staple foods of plant origin that often contain low levels or low bioavailability of these micronutrients. Biofortification aims to develop micronutrient-enhanced crop varieties through conventional plant breeding. HarvestPlus, the CGIAR's biofortification initiative, seeks to breed and disseminate crop varieties with enhanced micronutrient content that can improve the nutrition of the “hard to reach” (by fortification or supplementation programmes) rural and urban poor in targeted countries/regions. In attempting to enhance micronutrient levels in maize and wheat through conventional plant breeding, it is important to identify genetic resources with high levels of the targeted micronutrients, to consider the heritability of the targeted traits, to explore the availability of high throughput screening tools and to gain a better understanding of genotype by environment interactions. Biofortified maize and wheat varieties must have the trait combinations which encourage adoption such as high yield potential, disease resistance, and consumer acceptability. When defining breeding strategies and targeting micronutrient levels, researchers need to consider the desired micronutrient increases, food intake and retention and bioavailability as they relate to food processing, anti-nutritional factors and promoters. Finally, ex ante studies are required to quantify the burden of micronutrient deficiency and the potential of biofortification to achieve a significant improvement in human micronutrient status in the deficient target population in order to determine whether a biofortification program is cost-effective.     

不同品种橡胶幼树叶片微量元素含量差异研究

以7个橡胶树品种1年生幼树为研究对象,研究橡胶幼树叶片微量元素(铁、锰、铜、锌、硼)含量变化规律,并分析橡胶树产量水平与微量元素含量的相关性。结果表明:不同品种橡胶幼树叶片中,锰含量表现出随月份而逐渐增加的趋势,但铁、铜、锌、硼含量变化规律表现不一致。叶片铁、锰、铜、锌、硼含量较高的品种分别为‘粤390-1’‘热研7-33-97’‘热研8-79’‘热垦525’和‘粤390-1’,不同品种橡胶树叶片微量元素含量顺序均为:锰铁硼锌铜。橡胶树产量水平与叶片锌含量达极显著正相关(r=0.87),与叶片硼含量达显著负相关(r=-0.80)。     

Trace elements in spinach (Spinacia oleracea) cultivated in soil fortified with graded levels of iron

Trace elements in two varieties of spinach cultivated in soil with different levels of added iron were determined. Addition of iron to soil decreased potassium, sodium and magnesium contents in spinach markedly (p<0.05), while the contents of zinc, manganese and copper in spinach were not significantly altered (p>0.05). Differential behaviour of spinach varieties was found in the zinc, manganese and sodium contents.     

Contents of minerals in green leafy vegetables cultivated in soil fortified with different chemical fertilizers

Content of selected minerals in spinach (Spinacea oleracea) andambat chuka (Rumex vesicarius) cultivated in soil fortified withdifferent chemical fertilizers was determined in a pot experiment.Addition of NPK (Nitrogen, Phosphorus and Potassium) fertilizer alongwith micronutrients, iron and zinc, enhanced the concentration of zinc,iron and magnesium in selected green leafy vegetables markedly (p<0.05),while the concentration of copper was not altered significantly(p>>0.05). Potassium content in the green leafy vegetables was notaffected (p>0.05) by the addition of chemical fertilizers to soil.Spinach and ambat chuka differed remarkably in their mineral contents.Contents of potassium, zinc and copper were significantly high in spinach,while the contents of magnesium and iron were markedly high in ambatchuka (p<0.05).     

定安县耕地土壤微量元素含量及影响因素研究

采集耕地土壤198份样品，分析土壤有机质、pH和4种微量元素含量，并进行了相关性分析。结果表明：有机质含量较为丰富，全县平均含量达27.66 g/kg，各镇之间的差异较大；全县土壤呈酸性或强酸性反应，pH平均值为5.10；土壤有效铜含量符合正态分布，土壤有效铁和锰稍缺乏，铜和锌较丰富；有机质与锰、铜和锌呈正相关，与锰相关关系达极显著水平；pH同4种土壤微量元素均表现为正相关关系，与铁的相关性达到极显著水平。近期在进行农业生产时，应注重微量元素肥料的施用，避免缺素症状的发生，注意调节土壤酸碱度。     

Nutritional composition of selected green leafy vegetables,herbs and carrots

Six green leafy vegetables and herbs – spinach, amaranth, bengal gram, cauliflower, mint, coriander and carrots – were analyzed for moisture, protein,ascorbic acid, -carotene, total iron, ionizable iron (as % of total iron) in vitro iron (% of total iron), copper, manganese and zinc. Moisture content of the leaves and carrots varied from 75.1 percent (bengal gram) to 95.4 percent (carrot) and protein from 9.83 percent (carrots) to 30.9 (mint) percent. Ascorbic acid, -carotene, total iron and ionizable iron contents were at a maximum in case of bengal gram leaves whereas level of ionizable iron and in vitro iron as a percent of total iron was highest in carrots. Copper, manganese and zinc contents were maximum in spinach.     

有机物料改良苏打盐碱土增产玉米长期试验研究

连续7年盆栽试验表明,施用有机肥15、30、45、60、90 t/hm~2降低苏打盐碱土壤容重,增加土壤总孔隙度。玉米秸秆还田2、4、6 t/hm~2降低土壤容重,增加土壤总孔隙度。有机肥与秸秆还田均增大"土壤水库",降低土壤pH值,增加土壤有机质、碱解氮、速效磷和速效钾含量,土壤理化性质得到全面改善的同时减轻大气温室气体效应;促进玉米生长发育,增加了生物量及子粒产量。最佳处理为施用有机肥90 t/hm~2。