基于混合蛙跳算法的灌溉制度寻优应用研究

针对灌溉制度优化设计问题,以灌溉-产量灌溉制度模型为目标函数,随机生成灌溉制度,采用混合蛙跳算法对其进行优化,得到了最优灌溉制度。实例验证表明,混合蛙跳算法应用于灌溉制度寻优切实、可行,为灌溉制度寻优提供了一种新的方法。     

日光温室葡萄滴灌灌溉制度试验研究

根据葡萄不同物候期的需水特征,选择灌水量和灌水周期作为试验因素,开展日光温室葡萄滴灌灌溉制度试验.葡萄年生长周期持续352d,适宜的灌水次数为31次,平均灌水周期为12d,平均灌水定额为200m3/hm2,适宜的灌溉定额为6 200m3/hm2.照此灌溉制度进行灌水管理,葡萄产量可达3.75×104 kg/hm2以上.     

土地整理后喀斯特土壤不同粒级组分中养分含量研究

为探讨喀斯特山地土地整理后有效的土壤培肥模式,揭示不同粒级组分中养分含量的分布,以贵州省普定县陈家村进行土地整理后的坡地为例,进行小区施肥种植试验,研究不同施肥方式对整理后岩溶土壤养分培肥的影响。结果发现,各培肥模式中,施用农家肥、深松、使用本地蚯蚓对土壤有机质、全氮的改善效果较好,施用农家肥+尿素+过磷酸钙+氯化钾对增加土壤磷、钾养分的效果较好。同时发现0.002~0.02mm粒级组分中有机质和养分含量普遍高于其他粒级。     

氮肥基追比对烤烟生长及产量和品质的影响

研究了不同氮肥基追比对烤烟生长发育、物理特性、化学成分、烟叶产量和品质的影响。结果表明,基肥占60%、追肥占40%,且追肥在移栽后30d追施(T2处理)能提高烟叶的产量和改善烟叶的品质,与全部作基肥(T1处理)、基肥占40%和追肥占60%(T3处理)相比,烟叶的产量分别增加5.59%、2.21%,中上等烟比例分别增加4.89%、7.54%,且各处理间差异显著;其均价、产值也有不同程度的增加;烟叶化学成分的比例更为协调,感官质量总分显著高于其他处理。     

Effect of water management on dry seeded and puddled transplanted rice: Part 2: Water balance and water productivity

Labour and water scarcity in north west India are driving researchers and farmers to find alternative management strategies that will increase water productivity and reduce labour requirement while maintaining or increasing land productivity. A field experiment was done in Punjab, India, in 2008 and 2009 to compare water balance components and water productivity of dry seeded rice (DSR) and puddled transplanted rice (PTR). There were four irrigation schedules based on soil water tension (SWT) ranging from saturation (daily irrigation) to alternate wetting drying (AWD) with irrigation thresholds of 20, 40 and 70 kPa at 18–20 cm soil depth. There were large and significant declines in irrigation water input with AWD compared to daily irrigation in both establishment methods. The irrigation water savings were mainly due to reduced deep drainage, seepage and runoff, and to reduced ET in DSR. Within each irrigation treatment, deep drainage was much higher in DSR than in PTR, and more so in the second year (i.e. after 2 years without puddling). The irrigation input to daily irrigated DSR was similar to or higher than to daily irrigated PTR. However, within each AWD treatment, the irrigation input to DSR was less than to PTR, due to reduced seepage and runoff, mainly because all PTR treatments were continuously flooded for 2 weeks after transplanting. There was 30–50% irrigation water saving in DSR-20 kPa compared with PTR-20 kPa due to reduced seepage and runoff, which more than compensated for the increased deep drainage in DSR. Yields of PTR and DSR with daily irrigation and a 20 kPa irrigation threshold were similar each year. Thus irrigation and input water productivities (WP_I and WP_I+R) were highest with the 20 kPa irrigation threshold, and WP_I of DSR-20 kPa was 30–50% higher than of PTR-20 kPa. There was a consistent trend for declining ET with decreasing frequency of irrigation, but there was no effect of establishment method on ET apart from higher ET in DSR than PTR with daily irrigation. Water productivity with respect to ET (WP_ET) was highest with a 20 kPa irrigation threshold, with similar values for DSR and PTR. An irrigation threshold of 20 kPa was the optimum in terms of maximising grain yield, WP_I and WP_I+R for both PTR and DSR. Dry seeded rice with the 20 kPa threshold outperformed PTR-20 kPa in terms of WP_I through maintaining yield while reducing irrigation input by 30–50%.     

氮磷钾用量对烤烟红花大金元产质量的影响

[目的]明确德宏烟区中等肥力土壤下,氮磷钾施用量对烤烟红花大金元产质量的影响。[方法]在云南省梁河县勐养镇芒轩村进行了红花大金元品种不同施肥量的小区对比试验。[结果]随着施氮量和氮磷钾比例的增加,上、中、下3个部位的烟叶成分协调性趋于较好,红花大金元生育期、烟叶外观质量没有显著差异,但产量、产值、均价与之呈正相关,其中A3B2处理产量、产值、均价最高,但是化学成分较不协调。[结论]以纯氮用量105 kg/hm2指导红花大金元施肥,不仅提高烟叶的产质量,还可提高效益。     

不同施肥方式对绥粳4号品质的影响

[目的]研究绥粳4号的最佳施肥方式。[方法]采用二次回归正交旋转组合设计,4个因子分别为基施氮肥比例(X_1)、氮肥施入量(X_2)、磷肥施入量(X_3)、钾肥施入量(X_4),每个处理设置5个水平,研究不同施肥量、不同基施氮肥比例对黑龙江省第二积温带主栽水稻品种绥粳4号品质的影响。[结果]基施氮肥比例、氮、磷、钾对绥粳4号品质效应回归方程:Y=64.28+0.26X_1+0.12X_2+0.14X_3+0.11X_4-0.005X_1~2-0.000 7X_2~2-0.000 9X_3~2-0.001X_4~2+0.000 6X_1X_2+0.0002X_1X_4+0.0002X_2X_4-0.0001X_3X_4。当食味评分达最高值83.1时,绥粳4号的基施氮肥比例、施氮量、施磷量、施钾量分别为35.7%、112.8 kg/hm~2、70.8 kg/hm~2、51.7 kg/hm~2。[结论]该研究为水稻品种的合理施肥提供理论依据。     

基于地块综合资源优势度的土地供应时序及规模研究——以重庆两江新区工业开发区为例

为提供科学构建已征土地综合资源优势度评价指标体系的理论依据和方法借鉴,及为地方政府及开发区制定土地供应时序与规模相关计划和规划等提供实践支撑,以Arcgis空间分析技术为手段,采用了文献研究、实地调查和实证研究等多种方法,构建设计了包括4个评价目标共计19个指标的已征土地综合资源优势度评价指标体系,按不同供地用途类型设置评价指标基础权重并引入变权理论对权重予以修正,采用加权平均模型对资源优势度进行测算。结果表明,在现有综合资源条件下,两江新区供地面积最大的是产业发展用地,呈先增后减趋势;其次为城市建设用地,供地面积逐年增加;最少为公共服务用地,供地逐年减少。     

桉树人工林木材干燥皱缩特性的研究

本文研究了尾巨桉、尾圆桉和大花序桉等3种人工林桉树木材的干燥皱缩特性和干燥基准,分别测试了3种人工林桉树木材的表面开裂、端部开裂和内部开裂、干燥速度、干燥时间和皱缩等干燥皱缩特性指标,分析了木材细胞皱缩的形成机理和发生条件,木材构造对木材细胞皱缩的重要作用;比较了3种人工林桉树木材的干燥皱缩特性和干燥基准的差异,并对其进行了评价.结果显示,尾圆桉和大花序桉的干燥特性基本接近.     

氮肥不同施用时期对春玉米早衰的影响

采用盆栽试验研究氮肥不同施用时期下春玉米早衰特性。结果表明,合理的增加追肥次数能提高穗粒数和千粒重,进而提高玉米的籽粒产量。当氮肥分别在基施、拔节期与大喇叭口期1∶3∶1施用时,春玉米生育后期的穗叶叶绿素含量和SOD活性较一次性基施有不同程度的提高,而叶片形态指标和丙二醛(MDA)含量却降低,有效地延缓了玉米的衰老。对照(无氮肥)处理的穗叶叶绿体破裂解体,基粒和基质片层结构膨胀,导致叶片的叶绿素含量下降、光合能力降低而出现早衰。