Improving Water Productivity and Reducing Nutrient Losses by Controlled Irrigation and Drainage in Paddy Fields

Abstract

Controlled irrigation and drainage (CID) has received considerable attention as a reliable management practice for improving water quality and water productivity in rice production. This study aimed to evaluate the effects of CID on water productivity, nitrogen, and phosphorus losses in paddy fields. Treatments include alternate wetting and drying (AWD; lower limit of irrigation to-200 mm and upper limit of ponding water depth after rainfall to 60 mm), CID-I (lower limit of irrigation to-200 mm and upper limit of ponding water depth after rainfall to 200 mm), and CID-II (lower limit of irrigation to-500 mm and upper limit of ponding water depth after rainfall to 200 mm). Results showed that CID reduced irrigation water without a significant impact on grain yields and increased the irrigation water productivity by 14.6-51.5% compared with AWD. However, the percolation of CID may be increased, especially in a wetting year. The application of CID-II by combining yield with irrigation water productivity could be suitable and beneficial to rice crops. The average total nitrogen (TN) and total phosphorus (TP) concentrations of CID presented similar values or were significantly increased relative to AWD, indicating that the significant decreases in nutrient loads under CID were primarily due to reductions in surface runoff rather than changes in concentration. Ammonium nitrogen (NH 4 +-N) concentrations were clearly increased after fertilizer application in percolation water. Compared with AWD, the NH 4 +-N, TN, and TP leaching losses of CID-I were increased. The nitrogen and phosphorus leaching losses of CID-II were significantly increased relative to AWD and CID-I because of high nutrient concentrations and severe preferential flow. Therefore, CID potentially increased nitrogen and phosphorus loading to groundwater

Optimizing water-saving irrigation schemes for rice (Oryza sativa L.) using DSSAT-CERES-Rice model

“…Moreover, a constant water level throughout the growth stage of rice may be unfavorable to root growth and may affect grain yield [16] . In contrast to CD treatment, AWD can decrease irrigation volume by up to 38% with no yield reductions if implemented correctly [4] . Tan et al [53] found that AWD reduced irrigation water without a significant effect on grain yield and increased mean WUE by 16.9% compared with CD treatment.…”

“…The decrease may be attributed to the adverse influence on the rice root system by the reduced root oxidizing power as a result of the oxygen deficiency under a high ponded water table and continuous flooding in wet and normal years [55] . In terms of economic effects, Lampayan et al [4] found that water savings can increase farm income by as much as 17% in Vietnam, 32% in the Philippines, and 38% in Bangladesh. AWD had a relatively low frequency of irrigation events, which reduced the labor costs of irrigation.…”

“…To address this growing problem, approaches must be found that decrease irrigation water demand while maintaining a high grain yield of rice. Various water-saving technologies such as inadequate irrigation [1] and alternate wetting and drying (AWD) [4] have been developed to lower the water consumption of rice crop. AWD has produced good results in rice fields, but rainwater use efficiency (RWUE) in AWD has been founded to be inadequate because the depth of ponding rainwater in rice paddies is low [5] .…”

Effects of modelling studies on controlled drainage in agricultural land on reduction of outflow and nitrate losses–a meta-analysis

“…DWM is gaining popularity in other countries of the world due to improved quality of water flowing from drained agricultural fields to surface water. The practice has been tested on research facilities in several countries including Lithuania [ 40 ], Sweden [ 41 ], Denmark [ 39 ], Italy [ 42 ], China [ 43 , 44 ], Iran [ 45 ], India [ 46 ], Japan [ 47 ], and Egypt [ 48 ]. Unfortunately, the results of experimental field studies usually include a short measurement period of CD effectiveness.…”

Effects of Irrigation and Organic Mulching on the Abundance and Biomass of Earthworms

“…The potential for reducing water use in crop production varies significantly, from soil mulching to reducing soil evaporation [26]. In addition, the suitable application of controlled irrigation and drainage can save fresh water and reduce nutrient losses [27]. In areas where certain yields are failed to be achieved even through rational soil water management, irrigation as an agrotechnical measure may be improved.…”