节水灌溉水稻高产优质成因分析

分析了宁夏引黄灌区控灌条件下水稻各生育阶段根系、茎杆、叶片、分蘖等生态指标和土壤肥力、土壤水分等土壤理化状况及水稻产量构成因素、稻米品质、水稻发病及倒伏指标。结果表明 :控灌水稻有显著的节水增产效果 ,水稻单产 1 0 3 98kg/hm2 ,增产幅度为 5.3 %,节约灌溉用水量 70 57.5m3/hm2 ,节水幅度达3 8.8%。稻米品质也相应提高 ,控灌水稻粗蛋白含量提高 0 .2 1 %,整精米率提高 1 .59%,垩白度和垩白率降低1 .1 2 %和 0 .2 9%。同时抗病虫害和抗倒伏能力提高 ,病株率降低 1 9.8%,病叶率降低 1 5.4 %,倒伏率降低1 8.3 %。控灌通过稻田水分的合理调控 ,改善了稻田根层土壤性状 ,促进了根系的生长发育 ,有效地协调了茎、蘖、叶、穗、粒的生长 ,形成较合理的群体结构和较理想的株型 ,茎杆粗壮抗倒伏 ,蘖叶早生快发 ,有效分蘖率高 ,叶面积指数增减过程合理 ,穗大 ,实粒多 ,千粒重高 ,品质好。实现了宁夏水稻在控灌条件下的节水高产优质

Study on the Mechanisms of Yield-raising and Quality-improving for Paddy Rice Under Water-saving Irrigation

Some ecological indexes, as roots, stems, leaves and tillers in different growing stages, some soil physical and chemical properties, as soil fertility and soil moisture, and yield formation factors, grain quality, resistance to diseases and lodging in paddy rice were surveyed and analyzed systematically in Yellow River Irrigation Area in Ninxia Autonomous region. Experiment data indicate that benefits in water saving and yield raising in paddy rice are significant under control irrigation system. The yield on fields with control irrigation reaches 10398 kg/hm 2, an increase of 5.3%, compared to those with conventional irrigation system. 7057.5 m 3/hm 2 of irrigation water is saved at average for per hectare of land, a reduction of 38.8%, compared with the conventional irrigation method. Also, the production quality is improved correspondingly under control irrigation, as content of coarse protein increases by 0.21%, and percentage of integral fine rice rises by 1.59%. At the same time, the disease and lodging resistance of plants under control irrigation are improved obviously. The percentage of disease plants decreased by 19.8%, the percentage of infected leaves reduces by 15.4%, and the lodging rate reduces by 18.3%. The Experimental results reveal that through reasonable adjustment of water layer and soil moisture in paddy rice fields, the soil properties in crop root zone can be improved significantly, and a good grow condition for roots, stems, tillers, leaves, ears and grains can be established, and thus a relative reasonable canopy and forage structures can be formed. On the other hand, relative strong stalks is useful to prevent plants from lodging. Under control irrigation, tillers usually form relatively early and grow quickly, percentage of effective tillers and leaf area index increase rationally, ears are larger, number of stuffy grain per ear greater, weight per one thousand of grains higher and production quality better.