Physiology Character Research Of Rice Crop Cultivated In Different Water Condition

Water resource and its utilization in agriculture are mostly related to sustainable agriculture because of water shortage. Water is also the most important limit aspect of agriculture industry. Modern agriculture should not only satisfy with high yield, it is also need to pay more attention on resource and improving the efficiency of water using. Rice has the adaptation to moisture or dry condition, and it can be cultivated in aerobic condition with the same yield. As a new kind of water saving mechanism, aerobic cultivation of rice is gaining more and more attention for scientists, government, and farmers. A series of field experiment, imitating experiments in lab were carried out to study the responses of different cultivars of rice to aerobic cultivation, the N nutrition characteristics of rice in simulation water stress condition, and the effects of depth of groundwater on growth and rice yield.The main results are as follows.1. Significant differences of responses, i.e., growth situation, morphology, physiology and grain yields, to different water regimes were found in different cultivars. The root/shoot ratio of Guanglin Xiangjing growing in aerobic condition were 37.1% surpass that in waterlogged condition during the middle and later growth stage, and the ratios of Liangyou Peijiu, Yangdao 4 and Yanghan 1 (upland Cultivar as a CK) were also larger during the same stage among all the cultivars tested while the smallest root/shoot ratio, 30.1% less than that of waterlogged treatment, in Wuyujinj 3. Shanyou 63 had a biggest adsorption area of roots whereas smallest was found in Yanghan 1 and Yangdao 4 in aerobic cultivation. The order of relative yields of grain was as follows: Yanghan 1 > Shanyou 63 > Xieyou 63 > Yangdao 4 > 9520 > Wuyujing 3 > Guanglin Xiangjing > Liangyou Peijiu (96.9%, 76.3%, 74.2%, 61.6%, 49.5%, 43.9%, 43.7% and 43.0% respectively). Better adaptability to aerobic cultivation was found in Indicasthan Japonicas.2. The nitrogen nutrition absorbed by rice change apparently with different proportion of different nitrogen form in the water culture. To increase appropriate NO₃^--N may clear away efficiently the growth obstacle by water stress; Under simulation water stress condition, uptake of NO₃^--N by Shanyou 63, 9516, zhonghan 3, and Wuyujing 3 increase with the reduce of rate of NH₄⁺-N and NO3-N; The net uptake of NH₄⁺-N decrease, while NO₃^--N increase; Uptake of nitrogen nutrition by shanyou 63 seedling and 9516 and wuyujing 3 seedling increased with the reduce of rate of NH₄⁺-N and NO₃^--N; The rising amount of rice rope under simulating water stress condition is few than under single provision water.3.The moderation depth of groundwater is in favor of uptake and running to seed of N in rice crop. The increase of depth of groundwater made against P running from stem to seed. The more depth of groundwater disturbed K⁺ and NO₃^- running to stem in rice growth evening. The rice yield reduced with the increase of depth of groundwater. The content of solubility sugar and sucrose in grown rice rose with the increase of depth of groundwater (0-40 cm). When the depth of groundwater reach 50cm, the content of solubility sugar and sucrose in grown rice decrease sharply. In moderation range increasing groundwater depth will accelerate rice's accumulation of Ca²+ and Cl^-. Ca²+ and Cl^- may be concerned with the process of infiltration adjustment.