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Wang S.,North University of China | Wang S.,Key and Open Laboratory of Crop Water Requirements Regulation | Duan A.,Key and Open Laboratory of Crop Water Requirements Regulation | Duan A.,Chinese Academy of Agricultural Sciences | And 2 more authors.
Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering | Year: 2010

According to Monte Carlo method and 30 years meteorological data of Guangli irrigation district, precipitation of long series (500 years) were obtained. And basic parameters of winter wheat water consumption was studied though 2 years field experiments. Winter wheat irrigation schedules of all years were studied on this base, furthermore, irrigation patterns of all years were analyzed. The results showed that under irrigation quota on each application changed by 30 mm step-size, wintering period and jointing stage needed 30 mm irrigation water respectively, and the probability of highyield was 1% when irrigation quota was 60 mm. With wintering period and green stage irrigation for 30 mm respectively, jointing stage for 60 mm, the probability of highyield was 12% when irrigation quota was 120 mm. With wintering period and filling stage irrigation for 30 mm respectively, green stage and jointing stage irrigation for 60 mm respectively, the probability of highyield was 62.8% when irrigation quota was 180 mm. With jointing stage and heading stage irrigation for 60 mm respectively, others for 30 mm, the probability of highyield was 98.8% when irrigation quota was 240 mm. The research enriches the measures of winter wheat irrigation schedules, and can provide technical support of scientific water usage of winter wheat. Source


Meng Z.,Chinese Academy of Agricultural Sciences | Meng Z.,Key and Open Laboratory of Crop Water Requirements Regulation | Duan A.,Chinese Academy of Agricultural Sciences | Duan A.,Key and Open Laboratory of Crop Water Requirements Regulation | And 6 more authors.
Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery | Year: 2016

The effects of regulated deficit irrigation (RDI) on growth of roots and shoots of cotton plants were experimentally investigated during the growing seasons of 2013 and 2014 in pot-grown cotton (Gossypium hirsutum L. cv. Meimian 99B) under rain-proof shelter condition in Huang-Huai-Hai Region of China, aiming at offering theoretical basis for the establishment of RDI model for water-saving, high yield, high quality and efficiency of cotton crops. A two-factor randomize-block design was applied. The first factor was different growth stages of water deficit, including seedling stage (I), budding stage (II), flowering and boll-setting stages (III) and boll-opening stage (IV). Another factor was different degrees of water deficit, which were three levels controlled by soil relative water content, including light deficit (L), moderate deficit (M) and severe deficit (S) at stages of I to IV, corresponding soil relative water content were controlled at 60%~65% FC (Field capacity), 50%~55% FC and 40%~45% FC, respectively. Totally 12 water deficit treatments with six replicates were designed and applied. Additionally, an appropriate irrigation treatment (with soil relative water content controlled at 60%~70% FC at seedling stage, 60%~70% FC at budding stage, 70%~80% FC at flowering and boll-setting stages and 60%~70% FC at boll-opening stage) during the whole growing season was designed as control (CK) with 24 replicates. Root system parameters, such as root dry weight, root weight density and total shoot dry matter weight were measured synchronously in all treatments during water stress period and after re-watering, respectively. The results indicated that there were differences in effects of RDI on growth of roots and shoots in cotton due to both phenological stages and degrees of water deficit. Although water deficit didn't change the original trend of root growth in cotton, the growth rate of root was promoted. The growth of root was promoted significantly during moderate water deficit (50%~60% FC) at some growing stages, and there was a 'super-compensation effect' in root growth or the effect on delaying senescence of root after re-watering, and a higher ratio of root to shoot (R/S) was still retained at later stage of cotton growth. Therefore, it was indicated that moderate water deficit was suitable irrigation treatment for coordinating the relation of root and shoot growth of cotton. The results suggested that RDI should be adopted as an effective approach in regulating the growth of root and shoot in cotton plants. © 2016, Chinese Society of Agricultural Machinery. All right reserved. Source


Meng Z.,Chinese Academy of Agricultural Sciences | Meng Z.,Key and Open Laboratory of Crop Water Requirements Regulation | Sun J.,Chinese Academy of Agricultural Sciences | Sun J.,Key and Open Laboratory of Crop Water Requirements Regulation | And 6 more authors.
Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering | Year: 2010

Under the conditions of mobile rain-proof shelter and winter wheat cultivated in plots, effect of regulated deficit irrigation (RDI) on grain filling characteristics of winter wheat was investigated. A two-factor (growing stages introducing RDI and degrees of water deficit) randomized block designed experiment was employed in pot culture. The results showed that the grain filling course of winter wheat under RDI accorded with "S" growth curve of "slow-fast-slow", which could be simulated well by Richards equation. There were significant differences among some of filling characteristic parameters under different water deficit treatments such as maximum filling rate and its appearing time, average filling rate, filling duration, active growing duration, and filling duration time of each filling phase as well as 1000-grain weight (GW). Light water deficit in wintering period had the highest average filling rate (0.234 g/d per 100 grains), biggest filling rate (0.369 g/d per 100 grains), filling rate of the third phase (0.099 g/d per 100 grains), and 1000-GW (58.46 g). Results from correlation and stepwise regression analysis methods indicated that there were significant or very significant correlations among most parameters, in which biggest filling rate, average filling rate, active growing duration and filling rate of the third phase were significantly correlated to GW. Source

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