pH regulation is a complicated and comprehensive technique in the crop fertigation system. In this paper, a method is put forward to improve the quality of pH regulation, using artificial neural network to map a nonli...pH regulation is a complicated and comprehensive technique in the crop fertigation system. In this paper, a method is put forward to improve the quality of pH regulation, using artificial neural network to map a nonlinear relationship between pH interfering factor and the switching frequency of pH control valve, which achieves the dynamic feedforward compensation to the main control system.展开更多
The performance of Guatemala grass （Tripsacum laxum） under fertigation using hydroponic effluents at different dilution rates （effluent：water： 4：0, 3：1, 1：1, 1：3, 0：4） was compared to fertilisation using fa...The performance of Guatemala grass （Tripsacum laxum） under fertigation using hydroponic effluents at different dilution rates （effluent：water： 4：0, 3：1, 1：1, 1：3, 0：4） was compared to fertilisation using farmers＇ fertiliser rate of 475 kg 17：8：25/ha applied at planting ＋ 235 kg Sulphate of Ammonia/ha applied as top dressing one month after and 150 kg 17：8：25/ha applied after each harvest. Yield response obtained in plots fertilised using undiluted hydroponic effluents was 16.7% lower than that recorded in plots fertilised using farmers＇ fertiliser rate. The study showed that there-is potential for using hydroponic effluents （undiluted or diluted in the ratio of 3 HE： 1 water） in fodder production as it can provide sustainable yield in the range of 39.5-41.7 t/ha per harvest. Moreover, dilution rate of hydroponic effluents has a direct impact on crop development and fresh biomass yield. Fodder crop yield responded negatively to the increase dilution of hydroponic effluents from 4HE： 0 water to 3HE： 1 water, 1HE： 1 water and 1HE： 3 water. Consequently, the use of hydroponic effluents can eventually help to save on mineral fertiliser use and reduce cost of production while at the same time address environmental hazards related to hydroponic effluents disposal.展开更多
文摘pH regulation is a complicated and comprehensive technique in the crop fertigation system. In this paper, a method is put forward to improve the quality of pH regulation, using artificial neural network to map a nonlinear relationship between pH interfering factor and the switching frequency of pH control valve, which achieves the dynamic feedforward compensation to the main control system.
文摘The performance of Guatemala grass （Tripsacum laxum） under fertigation using hydroponic effluents at different dilution rates （effluent：water： 4：0, 3：1, 1：1, 1：3, 0：4） was compared to fertilisation using farmers＇ fertiliser rate of 475 kg 17：8：25/ha applied at planting ＋ 235 kg Sulphate of Ammonia/ha applied as top dressing one month after and 150 kg 17：8：25/ha applied after each harvest. Yield response obtained in plots fertilised using undiluted hydroponic effluents was 16.7% lower than that recorded in plots fertilised using farmers＇ fertiliser rate. The study showed that there-is potential for using hydroponic effluents （undiluted or diluted in the ratio of 3 HE： 1 water） in fodder production as it can provide sustainable yield in the range of 39.5-41.7 t/ha per harvest. Moreover, dilution rate of hydroponic effluents has a direct impact on crop development and fresh biomass yield. Fodder crop yield responded negatively to the increase dilution of hydroponic effluents from 4HE： 0 water to 3HE： 1 water, 1HE： 1 water and 1HE： 3 water. Consequently, the use of hydroponic effluents can eventually help to save on mineral fertiliser use and reduce cost of production while at the same time address environmental hazards related to hydroponic effluents disposal.
