华北冬小麦-夏玉米农田水分动态模拟研究

冬小麦-夏玉米连作是华北地区主要的粮食作物种植模式。根据华北季节性冻土区的特点,将全年划分为作物生长期与越冬期,分别建立了作物生长条件下农田水分运移模型、冻融条件下土壤水热运移模型。前一模型主要包括参照腾发量计算、腾发量分配、作物根系吸水、土壤表面蒸发、土壤水分特征参数和土壤水分运动等子模型;后一模型主要包括冻土水热耦舍迁移、地气水热交换等子模型。应用以上模型对冬小麦-夏玉米连作条件下的土壤水分过程进行模拟,根据北京永乐店试验资料对模型进行检验。模拟了不同降水水平年、不同灌溉处理下的农田灌溉制度及土壤水分过程,分析了降水、灌溉对农田蒸散、土壤水利用、深层渗漏等的影响。     

小麦对行免耕播种机试验研究

为解决一年可熟区小麦免耕播种作业的技术难题，提出了小麦对行免耕播种的思想；设计了2BMD-12型小麦对行免耕播种机．在玉米行何播种小麦．避开玉米秸秆和根茬。采用了新型高效的带状粉碎防堵机构，防堵性能优良。田问性能试验表明：2BMD-12型小麦对行免耕播种机在玉米直立秸秆和大量秸秆覆盖下。如能实现对行，可以顺利进行播种作业，满足作业质量和作物高产对施肥量的要求．适合我国中小地块、中小功率的特点。     

秸秆覆盖对冬小麦耗水特征及水分生产率的影响

2季冬小麦试验结果表明 ,秸秆覆盖具有减少土壤棵间无效蒸发的作用 ,冬小麦返青前 1 m土层贮水量在砂壤土条件下秸秆覆盖处理比无覆盖处理增加 2 %～ 2 5 .8% ,粘壤土条件下增加 2 %～ 1 4.5 %。返青前秸秆覆盖处理比无覆盖处理的日耗水量普遍小 ,返青后情况则相反。秸秆覆盖能够促进作物生长 ,与无覆盖相比 ,提高水分生产效率 4.6%～ 2 5 .2 %。     

不同节水灌溉技术的节水机理试验研究

根据甘肃省特殊自然地理条件，对于喷灌、滴灌、渗灌及波涌灌几种方式下，小麦和玉米两种作物的灌溉节水机理进行了对比试验研究，分析了不同节水灌溉方式下这两种作物的节水性和生育动态。试验结果表明，在降雨、灌溉水量和前期土壤特性一定的情况下，在喷灌、滴灌、渗灌及波涌灌几种节水灌溉技术中，渗灌的节水性最好，依次为滴灌、喷灌、波涌灌。小麦和玉米在渗灌条件下产量比滴灌、喷灌和波涌灌都高，小麦渗灌产量比滴灌增加7．6％，比喷灌增加13．1％，比波涌灌增加22．4％。玉米渗灌产量比滴灌增加1．3％．比喷道增加6．3％。     

春小麦高产叶龄模式的研究

本研究根据春小麦的叶龄进程，对水、肥、密等影响产量的主要因素进行优化组合，提出了旨在提高春小麦的产量及获得最佳效益的高产模式，为指导我国北方春小麦的生产提供了科学依据。     

冬小麦冬灌、秸秆覆盖、后期喷生长剂的节水增产效果的研究

试验证明，适时冬灌比早春灌，具有良好的防旱防冻、促根壮蘖增穗作用；小麦越冬期秸秆覆盖能保墒和提高土壤水分的调节能力，为当季小麦生长和套播玉米创造适宜的土壤水分条件；于小麦孕穗和灌浆期喷翠竹生长剂，其增粒增重作用显著。采取冬灌、越冬秸秆覆盖和孕穗、灌浆期喷生长剂等配套措施，可实现保墒与节水相结合，壮苗促蘖增穗与增粒增重的统一，节水增产效果显著。     

Performance of CERES-Rice and CERES-Wheat models in rice–wheat systems: A review

Rice–wheat (RW) systems are critical to food security and livelihoods of rural and urban poor in south Asia and China, and to regional economies in southeast Australia. The sustainability of RW systems in south Asia is, however, threatened by yield stagnation or decline, and declining partial factor productivity, soil organic C and water availability. Crop models potentially offer a means to readily explore management options to increase yield, and to determine trade-off between yield, resource-use efficiency and environmental outcomes. This paper reviews the performance of CERES-Rice and CERES-Wheat in Asia and Australia in relation to their potential application towards increasing resource use efficiency and yield of RW systems.

The performance of the models was evaluated using simulated and observed data on anthesis and maturity dates, in-season LAI and growth, final grain yield and its components, and soil water and N balances from published studies across Asia and Australia, and then by computing the statistical parameters for the major characters. Over the four data sets examined for anthesis and six for maturity dates, CERES-Rice predicted those dates fairly well (normalised RMSE = 4–5%; D-index = 0.94–0.95), but over the 11 sets for grain and 4 for biomass yield, the predictions were more variable (normalised RMSE = 23% for both; D-index 0.90 and 0.76, for grain and biomass, respectively). Model performance was poorer under conditions of low N, water deficit, and low temperatures during the reproductive stages. Over the three data sets examined, CERES-Wheat predicted the anthesis and maturity dates quite well (normalised RMSE = 4–5%; D-index = 0.94–0.99), and over eight sets for grain and two sets for biomass yield the model predicted them also reasonably well (RMSE = 13–16%; D-index = 0.86–0.97). Only one study evaluated the DSSAT RW sequence model with fairly satisfactory predictions of rice and wheat yields over 20 years with adequate N, but not the long-term change in soil organic C and N. Predictions of in-season LAI and crop growth, and soil and water processes were quite limited to investigate the robustness of model processes.

Application of models to evaluate options to increase water and N use efficiency requires the ability to perform well at the margin where deficit stress begins. While both models generally perform satisfactorily under water and N non-limiting conditions, the little evidence available suggests that they do not perform well under resource-limiting situations. We recommend that the models’ key processes under the water and N limiting conditions be further evaluated urgently. The DSSAT sequence model also needs to be further evaluated against observations for a range of locations and management using data from long-term experiments in RW systems.     

跨区作业经济效益影响因素剖析

根据2004年跨区作业调查,计算了联合收割机跨区机收的经济效益,并着重指出了跨区作业经济效益下降的实际问题;通过深入分析其中的原因,指出影响跨区作业经济效益的两大主要因素,是信息系统不完善和散机的无序流动。     

宁夏引黄灌区小麦垄作节水高产栽培研究

在宁夏引黄灌区进行小麦垄作栽培试验：春小麦全生育期在降水量为89.2 mm条件下,灌水量为3 183m3/hm^2,比传统的平作栽培的小麦灌水量5 131.5 m3/hm^2节水38%,抗倒伏,锈病、白粉病等发病轻;冬小麦全生育期在降雨量为101 mm、灌水量为4 582.5m3/hm^2条件下,4个冬小麦品种（系）垄作栽培试验的单产为6 691.5～7 350kg/hm2,垄作小麦播种量为210kg/hm2的处理比播种量为240kg/hm^2处理省种30%,而产量提高0.5%～7.9%.“烟农19号”和2个新培育的冬小麦品系2002AW5012、2002AW5011适于垄作,其产量水平为9 295.5～9 636kg/hm^2,比对照品种“宁冬6号”增产10.5%～14.5%.     

冬小麦节水高效优化灌溉制度模型应用研究

根据霍泉灌区田间试验资料,考虑水分亏缺的后效性,以冠层叶面积指数修正后的作物-水模型作为目标函数,建立二雏动态规划模型,计算冬小麦节水高效优化灌溉制度。结果显示,该模型充分反映了灌水时间、灌水定额和灌溉水量产生的冬小麦的产量效应,所建模型和参数确定较合理,在实践中更有实用性。