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Han Q.,Chinese Academy of Agricultural Sciences | Han Q.,Key Laboratory of Water saving Agriculture of Henan Province | Huang X.,China Agricultural University | Liu H.,Beijing Hydraulic Research Institute | And 3 more authors.
Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery | Year: 2013

An experiment on six Venturi injectors in Beijing was carried out. Based on theory studies, the differences of fertilization performance including fertilizer suction amount, the inlet discharge, the critical discharge and the critical pressure were analyzed and the regression models were built. It showed that the fertilizer suction amount and the inlet discharge were affected by the inlet and the outlet pressure directly. Domestic brands YR and RF were sensitive to the pressure fluctuation, while foreign models NF and AD could adjust to work environment better. The critical pressure of brands NF and AD-1were very low, thus these models have a long working range. In contrast, the critical pressure of the models RF and YR got to a half of the inlet pressure for a normal fertilization, and this means they have a short working range. Source

Sun H.,Chinese Academy of Agricultural Sciences | Sun H.,Key Laboratory of Water saving Agriculture of Henan Province | Li M.,Shihezi University | Li J.,Chinese Academy of Agricultural Sciences | And 7 more authors.
Paiguan Jixie Gongcheng Xuebao/Journal of Drainage and Irrigation Machinery Engineering | Year: 2014

Taking cotton as subject, cotton root distribution and water consumption were measured at each growth stage under five different dripper discharge (0.5, 1.0, 1.5, 2.0, 2.5 L/h). The results show that in the soil depth direction, cotton root length did not concentrate in the surface layer, but 10-30 cm under soil surface, and with dripper discharge increasing, the mostly concentrated place of root length transferred to shallow soil layer. The vertical distribution of cotton root weight could be described as the negative exponential function of soil depth, the largest root weight was observed in soil surface layer, and the ratio of deep root weight declined with the dripper discharge increasing. On the horizontal direction, the cotton root length and root weight all reduced gradually from the cotton stem to both sides of it, and with dripper discharge increasing, the ratio of root length (or root weight density) below the cotton stem decreased, but the ratio of root length (or root weight density) in both sides increased, cotton root changed from compact structure to extended structure. The field water consumption of cotton in the whole growth period showed as bimodal type curve, but with dripper discharge increasing, water consumption intensity at seedling stage increased, the moment of water consumption depth moving down delayed, and the highest water consumption period postponed. ©, 2014, Editorial Department of Journal of Drainage and Irrigation Machinery Engineering. All right reserved. Source

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