Effect of Alternate Wetting and Drying Irrigation Practice on Rice Crop Growth and Yield: A Lysimeter Study
Shashank Shekhar, Damodhara Rao Mailapalli, Narendra Singh Raghuwanshi
Abstract
Alternate wetting and drying irrigation practice in rice cultivation can save a significant amount of irrigation water. It involves irrigating rice fields alternately based on an irrigation triggering criterion and possibly influences the soil–plant–water system. In this study, field experiments were carried out for 3 years with three levels of soil matric potential heads (SMPHs) (no soil water stress: conventional irrigation, NS; 400 cm: mild soil water stress, MS; and 750 cm: severe soil water stress, SS) along with three levels of nitrogen (150 kg N/ha: high nitrogen, HN; 120 kg N/ha: medium nitrogen, and MN; 60 kg N/ha: low nitrogen, LN), and they were replicated three times. The daily ponding water depth and SMPHs at 10, 40, and 70 cm soil depths and agronomical parameters (plant height, number of tillers, biomass, and grain yield) were measured at regular intervals during the field experiments. The field data were used to assess water and nutrient dynamics and determine the crop production function. The grain yield under MS was almost similar to that under NS, but it was reduced by 9% under the SS practice. On the other hand, the MS and SS practices reduced 23 and 27% of the total available water depth, 6 and 15% of N uptake, 5 and 15% of P uptake, and 7 and 18% of K uptake, respectively, compared to NS. Furthermore, the effect of lesser uptake of water and nutrients on the crop yield was not significant in the case of MS. The MS + MN practice reduces the irrigation water without any significant reduction in grain yield, and this combination of water and nutrient management will be more appropriate for sustainable rice production.