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991.
Expected yield losses as a function of quality and quantity of water applied for irrigation are required to formulate guidelines for the effective utilisation of marginal quality waters. In an experiment conducted during 2004-2006, double-line source sprinklers were used to determine the separate and interactive effects of saline and alkali irrigation waters on wheat (Triticum aestivum L.). The study included three water qualities: groundwater (GW; electrical conductivity of water, ECw 3.5 dS m−1; sodium adsorption ratio, SAR 9.8 mmol L−1; residual sodium carbonate, RSC, nil) available at the site, and two synthesized waters, saline (SW; ECw 9.4 dS m−1, SAR 10.3 mmol L−1; RSC nil) and alkali (AW; ECw 3.7 dS m−1, SAR 15.1 mmol L−1; RSC 9.6 meq. L−1). The depths of applied SW, AW, and GW per irrigation ranged from 0.7 to 3.5 cm; the depths of applied mixtures of GW with either SW (MSW) or AW (MAW) ranged from 3.2 to 5 cm. Thereby, the water applied for post-plant irrigations using either of GW, SW or AW ranged between 15.2 and 34.6 cm and 17.1 and 48.1 cm during 2004-2005 and 2005-2006, respectively and the range was 32.1-37.0 and 53.1-60.0 cm for MSW or MAW. Grain yields, when averaged for two years, ranged between 3.08 and 4.36 Mg ha−1, 2.57 and 3.70 Mg ha−1 and 2.73 and 3.74 Mg ha−1 with various quantities of water applied using GW, SW and AW, respectively, and between 3.47 and 3.75 Mg ha−1 and 3.63 and 3.77 Mg ha−1 for MSW and MAW, respectively. The water production functions developed for the two sets of water quality treatments could be represented as: RY = 0.528 + 0.843(WA/OPE) − 0.359(WA/OPE)2 − 0.027ECw + 0.44 × 10−2(WA/OPE) × ECw for SW (R2 = 0.63); RY = 0.446 + 0.816(OPE/WA) − 0.326(WA/OPE)2 − 0.0124RSC − 0.55 × 10−4(WA/OPE) × RSC for AW (R2 = 0.56). Here, RY, WA and OPE are the relative yields in reference to the maximum yield obtained with GW, water applied for pre- and post-plant irrigations (cm), and open pan evaporation, respectively. Crop yield increased with increasing amount of applied water for all of the irrigation waters but the maximum yields as obtained with GW, could not be attained even with increased quantities of SW and AW. Increased frequency of irrigation with sprinklers reduced the rate of yield decline with increasing salinity in irrigation water. The sodium contents of plants increased with salinity/alkalinity of sprinkled waters as also with their quantities. Simultaneous decrease in potassium contents resulted in remarkable increase in Na:K ratio. 相似文献
992.
棵间土壤蒸发是控制性交替灌溉条件下农田土壤耗水的重要组成部分,为了了解沈阳地区潮棕壤土条件下大豆田不同控制性交替灌溉制度下的土壤蒸发变化规律,对土壤蒸发进行预报,采用Micro-lysimeters(MLS)对不同灌溉处理下的土壤蒸发量进行了测定,并建立了以气象因子、土壤含水率和叶面积指数为自变量的土壤蒸发的预报模型.结果表明,在本试验的条件下,各处理的相对土壤蒸发率(E/ET0)与表层土壤含水率(θ)的关系均呈指数函数形式,决定系数在0.71以上.各处理的E/ET0与LAI之间亦呈很好的指数函数关系,决定系数均在0.78以上. 相似文献
993.
北方半湿润滨海地区海水养殖废水灌溉菊芋研究 总被引:2,自引:0,他引:2
2007年3~10月,在山东莱州海洋863中试基地,研究了海水养殖废水灌溉条件下,耐盐能源植物菊芋的盐胁迫响应以及对氮、磷的吸收利用机制。结果表明:海水养殖废水灌溉条件下,菊芋地上部生物量(茎、叶)随着灌溉水盐度(S)的增加明显下降,盐度为9.46 g/L的养殖废水处理生物量仅为淡水处理(CK2)的62.5%;地下部生物量(根、块茎)与盐度之间的关系符合一元二次方程曲线,且当盐度为3.83 g/L时,地下部生物量取得最大值(0.205 kg/株)。养殖废水处理菊芋地上部氮浓度明显低于淡水处理,地下部则各灌溉水处理间氮浓度没有明显差异;磷浓度地上部各灌溉水处理间没有明显差异,但地下部养殖废水灌溉处理明显高于淡水处理,表明海水养殖废水灌溉可以促进菊芋对磷的吸收,但氮利用受到显著影响。通过氮、磷通量计算,进一步证实了这一结果。 相似文献
994.
995.
《Communications in Soil Science and Plant Analysis》2012,43(15-16):2282-2302
Efficient crop use of nitrogen (N) fertilizer is critical from economic and environmental viewpoints, especially under irrigated conditions. Cotton yield parameters, fiber quality, water‐ and N‐use efficiency responses to N, and irrigation methods in northern Syria were evaluated. Field trials were conducted for two growing seasons on a Chromoxerertic Rhodoxeralf. Treatments consisted of drip fertigation, furrow irrigation, and five different rates of N fertilizer (50, 100, 150, 200, and 250 kg N /ha). Cotton was irrigated when soil moisture in the specified active root depth was 80% of the field capacity as indicated by the neutron probe. Seed cotton yield was higher than the national average (3,928 kg/ha) by at least 12% as compared to all treatments. Lint properties were not negatively affected by the irrigation method or N rates. Water savings under drip fertigation ranged between 25 and 50% of irrigation water relative to furrow irrigation. Crop water‐use efficiencies of the drip‐fertigated treatments were in most cases 100% higher than those of the corresponding furrow‐irrigated treatments. The highest water demand was during the fruit‐setting growth stage. It was also concluded that under drip fertigation, 100–150 N kg/ha was adequate and comparable with the highest N rates tested under furrow irrigation regarding lint yield, N uptake, and recovery. Based on cotton seed yield and weight of stems, the overall amount of N removed from the field for the drip‐fertigated treatments ranged between 101 and 118kg and 116 and 188 N/ha for 2001 and 2002, respectively. The N removal ranged between 94 and 113 and 111 and 144 kg N/ha for the furrow‐irrigated treatments for 2001 and 2002, respectively. 相似文献
996.
997.
用新西兰引进的波纳、威诺阿、帕斯加、艾品、巴堪特和当地长期种植的芜菁6种冬春青绿饲料作物在云南省种羊场2个气候带种植,对各品种生物量及干鲜比进行比较分析.结果为芜菁生物量及含水量均较引进品种高;在引进品种中,高海拔山区威诺阿表现最佳,中海拔地区艾品较好. 相似文献
998.
999.
The responses of four wheat ( Triticum aestivum L.) varieties to soil moisture were determined by measuring plant parameters such as relative leaf water content (RLWC) and the chlorophyll, proline and sugar contents of the leaf over two seasons. Two levels of irrigation treatments were adopted: irrigated and rainfed. The rainfed plants had consistently higher amounts of proline and sugar but lower RLWC and chlorophyll content. As drought intensified, differences between the irrigated and the rainfed plants with respect to all of these characters increased. The RLWC values of the irrigated plants were significantly higher in the morning but lower values were found at noon, showing some recovery in the afternoon. 相似文献
1000.
遵照分类检索“以类索文,触类全貌,类目编排,严谨科学”的基本原则及本数据库独具专题综合性的特殊要求,以中国图管分类法为基础,优选有关1~4级类目、类号,显明简要的类目注释.并制定一套划分文献的规则,依类揭示本库所收录的节水农业文献信息,满足有关用户以类索文的需要。 相似文献