Influence of irrigation mode on winter wheat production and moisture changes of wheat fields under extreme rainfall patterns

This work studied the effect of irrigation measures on water changes and crop growth in wheat fields during extreme drought years with rainfall of only 47.7 mm during the wheat growth period. Field investigation was carried out in the low plains of Hebei Province. In the experiment, six water-saving wheat varieties were used, and five irrigation levels (0 mm, 75 mm, 150 mm, 225 mm and 300 mm designated as T0, T1, T2, T3 and T4, respectively) were set in the spring. Results showed that wheat yield ranged from 70.5 kg/hm2 to 7053.0 kg/hm2. With the increase in irrigation times, yield level gradually increased and was highest under the T4 treatment. The effect of irrigation mode on panicle number was different from that on yield. The T0 treatment group had the smallest panicle number, whereas the other treatment groups showed slight differences and no discernible trend. The range of 1000-grain weight of different varieties of wheat was 33.36–46.68 g. Except for the T0 treatment, all other treatments increased with the increase in irrigation times. The difference between panicle and grain number was irregular and related to varieties. When population difference was large, yield was related to population size. When the population difference was small, yield was correlated with 1000-grain weight. From the perspective of soil water changes, in the late growth stage, the water content of deep soil under T0 and T4 treatments was higher, whereas that under T1 and T2 treatments was lower. This result indicated that T1 and T2 irrigation modes were conducive for the full utilisation of water in deep soil and were efficient water use modes. T1 and T2 were water saving irrigation models in this study. These conclusions can provide a theoretical basis for guiding the selection of irrigation patterns for wheat cultivation during spring.