| 其他摘要 | Absence of water resource is the main restrictor to the economical development of our country. Water application in agriculture account for more than 70% of that of the whole country. However even if water exploration became more and more hard, the water use efficiency in agriculture was still a bit more low and water waste was serious. At the same time, amount of straw abandoned in crop production brought a lot of ecological and environmental problems such as air pollution by firing wasted straw and desiccation of soil et.al. For both persistent use of water resource and a better ecological environment, civil researchers put forward a method of integration of moisture conserving and water saving irrigation, which formed into a new agricultural system. With the spreading of straw mulch technology applied in irrigated region, a better effect was acquired in water saving and yield improving simultaneously. But the theory of irrigation with straw mulch was not so matured that can instruct the agriculture practice. So field experiment on current trait and irrigation quality of border irrigation with straw mulch was conducted in Yangling and related technological elements combinations were optimized. The result was as following:(1) During the growth period of winter wheat，five tillage modes under straw mulch were observed in the field. Cv value of Soil water content upright along the profile was that conventional tillage（0.1376）> stalk returning farmland and shallow plowing（0.1360）> conventional tillage under straw mulch（0.1309）>deep plowing under straw mulch（0.1265）>low stubble of corn.（0.1167）. During the growth period of winter wheat, soil moisture from 0 to 100 cm depth of low stubble of corn is the highest of 342mm among the five modes, conventional tillage is the lowest of 289mm and deep plowing under straw mulch is less than low stubble of 287mm and 307mm respectively, and stalk returning farmland and conventional tillage under straw mulch was moderate of 300mm.(2) Furrow length, inflow rate of unit width, and slope all had a significant effect on irrigation efficiency and distribution uniformity (DU) under straw mulch. In Shanxi, with middle soil texture, moderate infiltration ability, inflow rate of unit width from 3 to 4 l/(m·s), slope from 3~4‰,furrow length should be less than or upto 25m in borders irrigated by pump with straw mulch. Borders with inflow rate of unit width from 3~5 L/(m·s), slope from 3 to 5 ‰ , furrow length should be less than or equal to 40m. When furrow length from 45~50m, slope from 3～4‰, inflow rate of unit width should be in 6~9 L/(m·s). In guanzhong, shanxi, the flow rate of pump were from 15 to 20l/s, so borders width should be in 2~3m optimally and 4～6‰ for slope. Conversed slope had no significant effect on distribution uniformity, but it affected the irrigation efficiency significantly. So it should be avoided by reasonable management.(3) The commercial software，namely SRFR406，was used to simulate the performance of water advance with zeri-inertia model adopted. The results showed that the accurateness of this model application decreased with increased furrow length. rom 3~5ess than 40m, from 3~4ration ability, and 5mn irrigation e(4) It shows that application of border irrigation under straw mulch increased advanced hour of water flow, and with increased irrigation quantum soil storage ability of water was improved for protection to soil physical texture spontaneously. In different combination mode in this experiment application of straw mulch enhanced irrigation quality party and increased distribution uniformity of irrigation significantly. So optimized combination mode shoulde be used in border irrigation with straw mulch for a better irrigation quality. |
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