Impacts of Fertilization Alternatives and Crop Straw Incorporation on N_2O Emissions from a Spring Maize Field in Northeastern China

Spring maize is one of the most popular crops planted in northeastem China. The cropping systems involving spring maize have been maintaining high production through intensive management practices. However, the high rates of nitrogen （N） fertilizers application could have introduced a great amount of nitrous oxide （N2O） into the atmosphere. It is crucial for sustaining the maize production systems to reduce N2O emissions meanwhile maintaining the optimum yields by adopting alternative farming management practices. The goal of this study was to evaluate effects of alternative fertilization and crop residue management practices on N2O emission as well as crop yield for a typical maize field in northeastern China. Field experiments were conducted during the 2010-2011 maize growing seasons （from early May to late September） in Liaoning Province, northeastern China. N2O fluxes were measured at the field plots with six different treatments including no N fertilizer use （CK）, farmers＇ conventional N fertilizer application rate （FP）, reduced N fertilizer rate （OPT）, reduced N fertilizer rate combined with crop straw amendment （OPTS）, slow-release N fertilizer （CRF）, and reduced N fertilizer rate combined with nitrification inhibitor （OPT＋DCD）. The static chamber method combined with gas chromatography technique was employed to conduct the measurements of N2O fluxes. The field data showed that N2O emissions varied across the treatments. During the maize growing season in 2010, the total N2O emissions under the treatments of CK, FP, OPT, OPTS, and CRF were 0.63, 1.11, 1.03, 1.26, and 0.98 kg N ha-1, respectively. The seasonal cumulative N2O emissions were 0.54, 1.07, 0.96, 1.12, and 0.84 kg N ha1, respectively, under CK, FP, OPT, OPTS, and OPT＋DCD in 2011. In comparison with FP, CRF or OPT＋DCD reduced the N2O emissions by 12 or 21%, respectively, while the crop yields remained unchanged. The results indicate that the reduction of N-fertilizer application rate in combination with the slow-release fertilizer type or nitrification inhibitor could effectively mitigate N2O emissions from the tested field. The incorporation of crop residue didn＇t show positive effect on mitigating N2O emissions from the tested cropping system. The field study can provide useful information for the on-going debate on alternative N fertilization strategies and crop straw management in China. However, further studies would be needed to explore the long-term impacts of the alternative management practices on a wide range of environmental services.

Influence of high-fluorine environmental background on crops and human health in hot spring-type fluorosis-diseased areas

Drinking water-type fluorosis is the most harmful endemic disease in China with the largest number of sufferers. Although the implementation of the policy to alter water sources to lower fluoride level has effectively controlled the spread of this kind of endemic disease,its prevalence could not thoroughly be stopped because the high-fluoride environmental background in these endemically diseased areas could still do harm to human health through food chain. Therefore,it is necessary to conduct a more deep-going study on the drinking water-type fluoro-sis. To investigate the effect of high fluorine environmental background on crops and human health in the hot spring-type fluorosis-diseased areas,local water,paddy soil,rice,whole vegetables and soils around their roots were sampled for analysis. The results were compared with those of the control groups in fluorosis-free areas which are similar to the fluorosis-diseased areas both in natural background and in social background. It is indicated that rice and vegetables can accumulate water-soluble fluorine either in soils or in irrigating water,and different crops have different abilities of fixing fluorine. The contents of fluorine in different parts of vegetables in the fluorosis-diseased and fluorosis-free areas were statistically categorized. The results showed that the fluorine contents of roots,tubers,leaves and flowers of vegetables in the fluorosis-diseased areas are 3.56,1.17,3.07 and 3.23 mg/kg,respectively. However,comparisons showed that in the fluorosis-free areas,the fluorine contents are 2.17,0.70,1.91 and 2.52 mg/kg,respectively. Moreover,different parts of a crop also show significantly different fluorine fixation abilities. It is demonstrated that the fluorine contents of the strongly metabolic parts are relatively high. For example,the fluo-rine contents of roots,leaves and flowers of vegetables are much higher than those of stems. The fluorine fixation ability of seeds is very weak. In order to reduce the risk of human body’s exposure to fluoride,the impact of hot spring water on the capability of crops to fix fluorine should be reduced as much as possible. It is of great importance to prevent crops from being irrigated with hot spring water and it is advisable to grow crops with relatively low ca-pabilities to enrich fluorine,such as those with seeds or tubers as the main edible parts in the areas which are se-verely affected by hot spring water.

Using CropSyst to Simulate Spring Wheat Growth in Black Soil Zone of Northeast China

Available water and fertilizer have been the main limiting factors for yields of spring wheat, which occupies a large area of the black soil zone in northeast China; thus, the need to set up appropriate models for scenario analysis of cropping system models has been increasing. The capability of CropSyst, a cropping system simulation model, to simulate spring wheat growth of a widely grown spring cultivar, 'Longmai 19', in the black soil zone in northeast China under different water and nitrogen regimes was evaluated. Field data collected from a rotation experiment of three growing seasons (1992-1994) were used to calibrate and validate the model. The model was run for 3 years by providing initial conditions at the beginning of the rotation without reinitializing the model in later years in the rotation sequence. Crop input parameters were set based on measured data or taken from CropSyst manual. A few cultivar-specific parameters were adjusted within a reasonable range of fluctuation. The results demonstrated the robustness of CropSyst for simulating evapotranspiration, aboveground biomass, and grain yield of 'Longmai 19' spring wheat with the root mean square errors being 7%, 13% and 13% of the observed means for evapotranspiration (ET), grain yield and aboveground biomass, respectively. Although CropSyst was able to simulate spring production reasonably well, further evaluation and improvement of the model with a more detailed field database was desirable for agricultural systems in northeast China.

低温阴雨天气对农作物的影响

对黑龙江省部分地区20年以来4—5月5 cm土壤温度和降水量的研究。分析粮食减产的原因,得出的结论是由于土壤温度低、降水少严重影响农作物生长,导致粮食减产。针对低温阴雨天气带来的危害,应采取的应对措施和面对恶劣天气带来的不利因素进行补救措施进行了探讨。

宁夏地区春玉米灌溉需水量特征研究

【目的】提高宁夏地区春玉米的灌溉效率,优化农业资源配置。【方法】依据宁夏地区11个站点1960-2019年的气象资料,确定宁夏地区年际及春玉米生育期不同水文年型的有效降雨量;然后,利用ET 0 Calculator软件计算参考作物腾发量,并结合作物系数法计算作物需水量,求得宁夏地区年际及不同水文年型下春玉米各生育期的作物需水量、灌溉需水量、耦合度和水分盈亏指数。【结果】1960-2019年间,宁夏地区年有效降雨量波动较大(158.5~424.2 mm),北部引黄灌区、中部干旱带和南部山区春玉米生育期有效降雨量分别为123.9,205.4和334.4 mm。宁夏全区春玉米生育期需水量为482.0~690.7 mm,其中南部山区和中部干旱带春玉米需水量有降低趋势,而北部引黄灌区有增大趋势。北部引黄灌区、中部干旱带和南部山区春玉米灌溉需水量分别为566.8,413.0和147.6 mm;在枯水年、平水年和丰水年宁夏全区春玉米灌溉需水量分别为448.5,378.9和317.0 mm。南部山区降雨对作物需水量的满足程度最高,耦合度为0.70,是北部引黄灌区的3.89倍。【结论】宁夏南部山区应以集雨技术为基础发展雨养玉米种植;北部引黄灌区和中部干旱带需要大力发展节水灌溉,其中在北部引黄灌区春玉米大喇叭口期、抽雄期和乳熟期需要分别补灌87.2,79.6和275.6 mm,在中部干旱带需要分别补灌65.7,62.4和212.8 mm。

基于闪烁通量和土壤水分的春玉米干旱研究

为了识别河北省怀来县春玉米生长季内不同生育期的干旱情况。基于大孔径闪烁仪观测系统的数据,本研究用河北省怀来县2021年春玉米的实际蒸散量代替潜在蒸散量,计算了修订的水分亏缺指数(RCWDI)。根据土壤相对湿度得到的春玉米实际干旱等级,重新构建了RCWDI的干旱等级,并利用2019年的数据进行了验证。结果表明:2021年怀来县春玉米生育期内降水量和实际蒸散量之间有显著的相关关系,降水量与蒸散量差值的累积值可以反映春玉米的干旱状况。2021年怀来县春玉米干旱主要发生在播种到拔节期。2019年利用RCWDI获得的干旱等级与基于土壤水分得到的干旱等级相似度高达80%。研究表明基于闪烁通量修订的水分亏缺指数及其干旱等级具有一定的适用性。

Exploring the Potential Impacts of Climate Variability on Spring Wheat Yield with the APSIM Decision Support Tool

Assessing the impacts of climate variability on agricultural productivity at regional, national or global scale is essential for defining adaptation and mitigation strategies. We explore in this study the potential changes in spring wheat yields at Swift Current and Melfort, Canada, for different sowing windows under projected climate scenarios (i.e., the representative concentration pathways, RCP4.5 and RCP8.5). First, the APSIM model was calibrated and evaluated at the study sites using data from long term experimental field plots. Then, the impacts of change in sowing dates on final yield were assessed over the 2030-2099 period with a 1990-2009 baseline period of observed yield data, assuming that other crop management practices remained unchanged. Results showed that the performance of APSIM was quite satisfactory with an index of agreement of 0.80, R2 of 0.54, and mean absolute error (MAE) and root mean square error (RMSE) of 529 kg/ha and 1023 kg/ha, respectively (MAE = 476 kg/ha and RMSE = 684 kg/ha in calibration phase). Under the projected climate conditions, a general trend in yield loss was observed regardless of the sowing window, with a range from ?-24% to -94% depending on the site and the RCP, and noticeable losses during the 2060s and beyond (increasing CO2 effects being excluded). Smallest yield losses obtained through earlier possible sowing date (i.e., mid-April) under the projected future climate suggested that this option might be explored for mitigating possible adverse impacts of climate variability. Our findings could therefore serve as a basis for using APSIM as a decision support tool for adaptation/mitigation options under potential climate variability within Western Canada.

The Effect of Organo-Mineral Fertilizer Applications on the Yield of Winter Wheat, Spring Barley, Forage Maize and Grass Cut for Silage

Biosolids were applied with urea to produce a granulated organo-mineral fertiliser (OMF) for application by farm fertiliser equipment to a range of agricultural crops. The recommended rates of nitrogen, phosphate and potash were calculated for the test crops using “The Fertiliser Manual”, which assesses the nutrient requirement based on previous cropping, rainfall and soil index. The OMF produced similar crop yields compared to ammonium nitrate fertiliser when applied as a top-dressing to winter wheat, forage maize and grass cut for silage in the cropping years 2010 to 2014. In 2012 the grain yield of spring barley top-dressed with OMF was significantly lower than the conventional fertiliser treatment, due to dry conditions following application. For this reason it is recommended that OMF is incorporated into the seedbed for spring sown crops and The Safe Sludge Matrix guidelines followed. The experimental work presented shows that OMF can be used in sustainable crop production systems as a source of nitrogen and phosphorus for a range of agricultural crops.

Impact of Climate Variability on Yield of Spring Wheat in North Dakota

Agricultural production is highly dependent on the climatic variability of the specific regions. Differential climatic and soil conditions bring about changes in yield, quality of crops thus affecting the economy. This study evaluated the impact of variability in different climatic factors keeping the other factors constant on spring wheat production in North Dakota from 2007 to 2011. The spring wheat yield mainly depends on the climatic changes during growing periods April to September. Average maximum air temperature was significantly different from April to September except June from 2007 to 2011. High average minimum and maximum air temperatures during planting time increase yield and planting area for 2010. In 2011, low mean soil temperature, excess rainfall in April caused low yield of spring wheat. The unmitigated climate variability will result in declines in yields. So, adoption of sustainable agriculture practices helps the farmers to develop the different practices for their farms.

河套灌区麦后复种毛叶苕子与化学氮肥减量配施对作物产量和土壤肥力的影响

研究河套灌区春小麦后复种毛叶苕子还田条件下,小麦季不同施氮水平对小麦-绿肥轮作体系产量、土壤肥力及经济效益的影响,旨在为河套灌区绿肥还田下小麦氮肥减量提供科学依据。2018—2020年在内蒙古巴彦淖尔市农牧业科学研究所园子渠试验站进行田间定位试验,采用随机区组试验设计,以麦后夏休闲+小麦常规施氮为对照(CK),设置麦后复种毛叶苕子50%翻压还田+小麦减氮10%(GN_(90))、减氮20%(GN_(80))和减氮30%(GN_(70))。与CK相比,2019年GN_(80)处理显著提高春小麦产量12%,2020年GN_(90)、GN_(80)显著增加了春小麦产量,增幅分别为16%和13%。春小麦季减氮对复种毛叶苕子鲜草产量没有影响,2020年毛叶苕子产量仅为2019年的52%。麦后复种毛叶苕子结合氮肥减量10%~30%显著增加了春小麦穗粒数及千粒重,实现增产稳产。与CK比较,2019年不同处理对土壤全量及速效养分含量影响不显著;2020年GN_(90)处理显著提高了土壤有机质含量,增幅为37%。GN_(90)、GN_(80)、GN_(70)处理的土壤全氮含量分别显著增加了40%、23%、17%,GN_(90)、GN_(80)处理显著提高了有效磷含量,增幅分别21%、23%。2019年GN_(90)、GN_(80)、GN_(70)经济效益较CK分别增加39%、33%、29%;2020年由于毛叶苕子牧草收益大幅降低,导致GN_(80)、GN_(70)处理的纯增收益较CK分别低3%、5%。河套灌区麦后复种毛叶苕子50%翻压还田,后茬小麦季减氮10%可以提高小麦产量、培肥土壤,同时具有较高经济生态效益,是一种适宜河套地区春小麦种植的绿色高效栽培模式。

春小麦叶片气体交换与产量对干旱响应的阈值差异

叶片气体交换过程是作物干物质及产量形成的基础,在干旱发展过程中作物叶片气体交换对水分胁迫存在阈值响应,众多相关生理指标也以此为基础用于监测作物受旱状况。然而作物叶片气体交换过程与产量对干旱的响应阈值是否具有同步性,目前尚不清楚,这在一定程度上影响了利用作物生长期叶片气体交换相关生理指标监测农业干旱的准确性。本研究通过控制试验确定春小麦叶片气体交换对干旱的响应阈值,并利用该阈值特征参数化春小麦生长模型,从而设计水分控制模拟试验,分析春小麦产量对干旱的阈值响应特征及其与叶片气体交换指标阈值的差异。结果表明:春小麦气孔导度对土壤有效含水量的响应阈值为0.50,大于蒸腾速率与净光合速率的响应阈值(0.40)。用净光合速率对土壤有效含水量的响应阈值参数化春小麦生长模型,能够准确模拟春小麦地上部生物量和产量的变化。春小麦地上部生物量与产量对根系层土壤有效含水量的响应阈值为0.18,明显小于叶片气体交换指标对土壤有效含水量的响应阈值。证明了利用作物生育期间叶片气体交换等生理指标表征作物受旱状况,反映作物最终产量降低程度会存在一定问题。本研究结果可为农业干旱监测、预测及干旱影响评估提供参考依据。

施氮量和灌溉定额对引黄灌区麦后复种油菜产量和水氮利用的影响

为探讨小麦后复种油菜对小麦茬残留氮素吸收利用及水氮利用的影响,以期为麦后土壤残留氮素有效利用和农业面源污染阻控提供理论依据,通过田间定位试验,研究了小麦茬施氮量[常规施氮(270 kg∙hm^(−2))、减施氮肥(202.5 kg∙hm^(−2))和不施氮(0 kg∙hm^(−2))]和灌溉定额[常规灌溉(400 mm)、节水20%(320 mm)和节水40%(240 mm)]对复种油菜的产量、氮素吸收量以及0~100 cm土壤含水率和矿质氮动态变化的影响,并进行了两季作物的氮素平衡分析。结果表明,小麦茬残留氮素对油菜产量和氮素吸收量有显著影响,氮肥后效与小麦茬的施氮量呈正比。小麦茬常规施氮270 kg∙hm^(−2)时油菜产量和氮素吸收量最高,分别为6640 kg∙hm^(−2)和25.7 kg∙hm^(−2),较小麦茬减施氮肥与不施氮分别增加11.8%与43.5%和14.8%与58.8%;小麦茬灌溉定额对油菜产量无显著影响,但对氮素吸收量有显著影响,常规施氮处理下常规灌溉处理油菜氮素吸收量较节水处理增加9.6%~10.2%。与油菜播前相比,油菜收获后施氮处理0~100 cm土层土壤矿质氮降低18.8~96.1 kg·hm^(−2);常规施氮处理较减氮和不施氮处理增加了油菜对残留氮素吸收能力。油菜翻压还田并经过冬季的冻融后,在下一季小麦播前,0~100 cm土层的土壤矿质氮增加86.1~171.8 kg·hm^(−2),增加量与小麦茬的施氮量呈正相关。常规施氮+常规灌溉定额0~100 cm土壤贮水量变化较小,氮肥后效显著提高了油菜灌溉水利用效率和水分利用效率及降水生产效率,常规施氮+节水20%处理灌溉水利用效率和降水生产效率最高,而常规施氮+节水40%处理油菜水分利用效率最高。在本试验条件下,减氮+节水20%处理的氮肥累积利用率最高,达89.8%。小麦茬施氮量为270 kg·hm^(−2),灌溉定额为320~400 mm显著提高了复种油菜的产量、吸氮量、水分利用效率和灌溉水利用效率及降水生产效率,并降低了施氮处理土壤矿质氮含量。而油菜翻压还田经过冬季冻融后显著增加了土壤矿质氮含量。

民勤蜜瓜连体拱棚一年两熟栽培技术

蜜瓜连体拱棚一年两熟栽培是民勤县近年来试验示范推广的新技术、新模式,在民勤蜜瓜产业高质量发展上起着承前启后、接续市场供应的作用。为给蜜瓜连体拱棚栽培提供技术指导,基于多年试验研究和生产实践,从连体拱棚建设、品种选择、穴盘育苗、温室管理、病虫害防治等方面总结了民勤蜜瓜连体拱棚一年两熟栽培技术。

不同轮作模式和施氮水平对春小麦产量和品质的影响

通过优化轮作模式和施氮制度,探究春小麦产量和品质的变化,为建立农田高产、优质的生产方式提供科学依据。本研究在河西绿洲灌区武威市进行,试验采用完全随机区组设计,设小麦连作(W)、春小麦-箭筈豌豆-春小麦-箭筈豌豆(WV)、春小麦-冬小麦-箭筈豌豆(WWV)和春小麦-冬油菜-箭筈豌豆(WRV)4种种植模式;2年轮作周期内设置3种施氮水平,分别为不施氮(N_(0))、减量25%270 kg/hm^(2)(N_(1))和传统施氮360 kg/hm^(2)(N_(2))。通过对小麦干物质积累量、产量及品质的测定,以期为该区建立合理的种植模式和施氮制度,进而提高耕地产能。结果表明:不同施氮水平下,干物质积累量在拔节至灌浆期迅速增长,N_(2)处理在开花期具有最高的干物质积累量,N_(1)较N_(2)处理降低了10.1%和10.6%;与连作模式相比,WRV、WWV和WV 3种轮作模式提高了小麦干物质积累量,在2020年和2022年平均提高14.9%和15.7%、10.9%和11.8%、8.6%和8.1%。减量施氮处理下,降低了小麦千粒重、单位面积穗数和穗粒数,但轮作模式提高了千粒重、单位面积穗数和穗粒数,产量得到了提高;与N_(2)相比,N_(1)处理产量降低了11.5%和12.5%,与连作模式相比,WRV、WWV和WV 3种轮作模式产量分别提高18.5%和23.8%、10.3%和16.1%、6.0%和11.5%。轮作模式结合氮肥可以有效地提高籽粒品质,其中籽粒蛋白含量、沉降值及湿面筋含量都有所提升。相关性分析显示,轮作模式结合氮肥对作物产量具有一定的提升效应,这主要是由于产量构成因素的协同提高。不同施氮水平下,春小麦-冬油菜-箭筈豌豆轮作模式对农田春小麦产量及品质有明显的提升效应,因此,可作为西北绿洲灌区提高农田小麦产量和品质的一种新的种植模式。

基于Softmax分类器的小春作物种植空间信息提取

[目的]使用浅层机器学习分类方法和多光谱遥感影像快速准确提取研究区小春作物(油菜、小麦)种植空间信息。[方法]选择研究区小春作物识别最佳时期的Sentinel 2A MSI多光谱影像,融合得到10 m分辨率影像,然后降尺度生成15、20、30 m分辨率影像,结合地面调查数据,建立油菜、小麦、林地、居民地、水体等典型地物感兴趣区,训练Softmax分类器,基于不同空间分辨率影像提取油菜、小麦种植空间信息。[结果]①基于Softmax分类器和10 m分辨率融合影像的小春作物分类总体精度为90.02%,Kappa系数为0.8344,其中油菜生产者精度和用户精度分别为93.14%、91.42%,小麦的分别为87.93%,98.09%;②Softmax法的小春作物分类精度随影像空间分辨率下降而降低,15、20、30 m分辨率影像的分类精度较10 m的分别下降9.80%、12.04%和13.04%,Kappa系数依次减少0.1538,0.1873和0.2088;③15、20、30 m分辨率影像的油菜分类精度较小麦的低,影响因素为油菜花期和种植地块破碎分散。[结论]Softmax分类器在10~30 m中高分辨率影像小春作物分类中具备较高的精度,可作为常规方法应用于业务化的作物监测工作。

虚实并存耕层提高春玉米产量和水分利用效率

为了探明耕层构造对春玉米产量及水分利用效率的影响，在农业部阜新农业环境与耕地保育科学观测实验站利用长期定位试验，设置了虚实并存耕层（furrow loose and ridge compaction plough layer，FLRC）、全虚耕层（all loose plough layer，AL）、全实耕层（all compaction plough layer，AC）、以及作为对照（controlled trial，CK）的上虚下实耕层（up loose and down compaction plough layer，ULDC）4种耕层结构，研究了不同耕层构造对春玉米产量及水分利用效率的影响。利用2011和2012年数据分析结果表明，不同耕层构造对春玉米产量影响显著（P〈0.05），2a平均表现为FLRC＆gt;AL＆gt;ULDC＆gt;AC，FLRC和AL比CK分别增加16.39%、5.30%，收获指数在0.38～0.44之间。在平水年（2011）和丰水年（2012）虚实并存耕层和全虚耕层均可有效蓄积降水，改善土壤水分状况，明显提高玉米的降水利用效率，2011年FLRC比ULDC提高11.95%（P〈0.05）；2012年FLRC和AL分别比CK提高21.23%（P〈0.05）和12.43%（P〈0.05）；不同降雨年型和不同耕层结构对作物水分利用效率（water use efficiency， WUE）影响不同，2011年FLRC比CK增加15.68%（P〈0.05），2012年FLRC比CK增加23.13%（P〈0.05），2a平均提高18.43%。综合分析认为，虚实并存耕层是提高土地生产力和农田水分利用效率的最优耕层结构。该研究为辽西旱作农业区合理耕层构建、确定适宜的耕作技术和实现作物的高产稳产提供参考。

华北平原旱地不同熟制作物产量、效益和水分利用比较

针对华北平原地下水超采严重,通过研究雨养旱作条件下不同熟制的产量、投入产出和水分利用效率,探索华北平原缺水区雨养旱作条件下的节水种植制度,可为地下水超采提供技术支撑。以当地主栽种植模式冬小麦和夏玉米一年2熟种植和春玉米一年1熟种植为研究对象,通过大田试验对雨养旱作条件下冬小麦、夏玉米和春玉米3种作物构成的2种种植制度的产量、耗水、投入、产出进行分析。试验于2007—2013年在中国科学院栾城农业生态系统试验站进行,该站为华北平原高产农区的典型代表。试验共设2个处理,T1为冬小麦-夏玉米一年2熟制,T2为春玉米一年1熟制。T1中的冬小麦生育期为每年的10月中上旬至翌年的6月中旬,夏玉米为6月中下旬至10月上旬,冬小麦品种大部分年份为‘科农199’,夏玉米品种为‘郑单958’。T2中春玉米的生育期为每年的5月中下旬至当年的9月上中旬,品种为‘农大108’、‘浚单20’、‘郑单958’和‘先玉335’。试验区从2007年9月至2013年6月一直未灌溉,为雨养旱作条件。研究结果表明,雨养旱作条件下,冬小麦产量基本稳定;夏玉米和春玉米产量随年型不同波动较大,尤其是夏玉米产量受播种时土壤含水量的影响较大,很多年份由于干旱少雨,玉米出苗时间推迟,导致玉米产量大幅度降低。T1比T2虽然具有明显的产量优势,增产34.1%,但由于冬小麦生产投入较高,T1的净收益比T2低279.97元·hm-2。3种作物的生产投入中,农资和机械投入比例最大,劳动力投入占很小比例,农资投入中,化肥投入最高;3种作物的产投比分别为1.42、2.66和3.42,雨养旱作条件下冬小麦的产投比最低,春玉米最高。从作物的耗水结构分析,冬小麦生育期降雨较少,以消耗雨季储存于土壤中的土壤水分为主,春(夏)玉米生育期降雨较多以消耗降雨为主。目前,生产上正在自发地压缩冬小麦的种植面积,春玉米一年1熟种植面积迅速增加。因此,在保证区域粮食安全的条件下,通过调整农业种植结构可以控制水资源的过度开采,保证农业持续发展。

辣椒剪枝再生栽培与春茬栽培比较研究

以兴蔬皱皮辣椒为试材,对越冬茬(2月3日和24日剪枝)辣椒植株和春茬(2月3日和24日移栽)栽培辣椒植株进行物候期、早期产量及其构成因素、果实相关性状、病虫害发生情况比较。结果表明:同一天剪枝、移栽的辣椒植株,剪枝再生植株的现蕾期、始花期、始收期均早于春茬移栽植株;剪枝再生植株的早期单株果数、单株果质量、产量极显著高于春茬移栽植株,与同一天移栽的春茬辣椒相比,2月3日、2月24日剪枝再生栽培辣椒的产量分别提高了32.36%、45.40%;剪枝再生植株的果实小于春茬栽培的,单果质量、商品果纵径、横径均显著小于春茬栽培的,春茬移栽植株果实的果肉比剪枝再生植株的厚,差异达极显著水平;剪枝再生植株的病虫害发生较严重,较大面积的暴发了疫病,且白粉虱和红蜘蛛为害较重,春茬移栽植株的病虫害发生较少。

灰色关联度分析在云南小春作物产量预报中的应用

将灰色关联度分析法与相关分析法分别应用于云南小春作物产量预报因子的筛选,并将用两种方法选出的因子用于2004年的产量预报。对比其预报结果:灰色关联度分析法筛选出的气象因子,更能体现其生物学意义;可以通过计算灰色关联度来找到主要因子、剔除次要因子,以抓住主要矛盾,减少计算量。

模拟增温和降水变化对半干旱区春小麦生长及产量的影响

为了探索和验证未来气候变化对半干旱区春小麦生产的影响,了解春小麦生长发育和产量对增温和降水变化协同响应的基本特征,利用开放式增温系统和水分控制装置,设置不同水分和温度梯度来模拟气候变化对半干旱区春小麦的影响。结果表明:正常和增加30%降水条件下,增温2.0℃使春小麦株高降低。在不增温和增温2.0℃条件下,增加30%降水使春小麦株高增加;正常和增加降水条件下,增温的叶面积指数比不增温的低。正常和增温条件下,水分对叶面积指数的影响规律性不是很明显;增温和增水协同条件下的株高、叶面积指数小于不增温和正常降水条件下的株高、叶面积指数;增温导致叶绿素含量降低,增温情况下增水会使叶绿素含量提高;正常和增加降水条件下,增温的干物质质量比不增温的低。正常和增温条件下,降水增多则有利于干物质质量的积累;营养生长阶段和生殖生长阶段,在正常和增加降水条件下,增温对叶的分配系数有负效应,增水为正效应。增温对茎的分配系数有正效应,增水为负效应。增温对穗的分配系数有负效应,增水为正效应;增加降水对春小麦的产量有正效应,而增温则不利于产量的提高,即便是在增加降水的情况下,增温还是对产量有不利的影响。研究结果为中国半干旱区春小麦对全球气候变化下的敏感性及适应性提供理论参考。