Fuzzy comprehensive evaluation on water consumption characteristics and yield of summer corn under different furrow irrigation patterns

Abstract: Yield and water consumption are two of important indicators of crop water-saving and high-yield cultivation. In order to verify the feasibility of fuzzy mathematics in evaluation of water consumption characteristics and yield of summer corn, this study an improved fuzzy comprehensive evaluation model was adopted. An experiment from June 2012 to September 2012 was conducted in Henan Key Laboratory of Eater-saving Agriculture Farming Water Test site of North China University of Water Conservancy and Electric Power(34o51′ N, 113o49′ E). We designed two kinds of planting pattern including wide ridge furrow irrigation and conventional furrow irrigation. Meanwhile, relative soil moisture of 60%, 70%, 80% was used for each planting pattern. Crop water consumption of different growth stages of summer maize was determined. Yield and its components were measured. Meanwhile, an improved fuzzy comprehensive evaluation was done after data about yield and water consumption were standardized. The resulted showed that the fuzzy comprehensive evaluation indexes of water consumption respectively were 0.37358, 0.32770, and 0.29872 for wide ridge furrow irrigation lower limits with relative soil moisture of 60%, 70%, and 80%, respectively. The high index indicated lower water consumption. Thus, the water consumption of summer maize for wide ridge furrow irrigation lower limits with relative soil moisture of 60%, 70%, and 80% should be highest for the treatment of irrigation lower limits with relative soil moisture of 80% and lowest for that of 60%. According to the field experiment, the water consumption during the whole growth stage of maize was 349.66, 398.64, and 442.62 mm for wide ridge furrow irrigation lower limits with relative soil moisture of 60%, 70%, and 80%, respectively. The evaluation result was well confirmed by the results of field experiment for the wide ridge furrow irrigation treatment. Similarly, The evaluation results were consistent with that from field experiment for the conventional furrow irrigation treatment. Based on the improved fuzzy evaluation, the relative soil moisture of 70% should have the highest yield with the largest evaluation index of 0.34296 for the wide ridge furrow irrigation treatment, which was supported by the measured yield (7853.39 kg/hm2). Consistent with the evaluation index, the measured yield for the wide ridge furrow irrigation was higher for the relative soil moisture of 80% than the relative soil moisture of 60%. The similar trend was found for the conventional furrow irrigation treatment. In comparison with the other wide ridge furrow irrigation lower limit treatments, the relative soil moisture of 70% was also higher. It suggested that the irrigation limit of the relative soil moisture of 70% was best than the other two irrigation limits for the wide ridge furrow irrigation for both yield and water use efficiency. However, for the conventional furrow irrigation treatment, the irrigation limit of the relative soil moisture of 60% was highest in the water use efficiency, but the irrigation limit of the relative soil moisture of 70% was highest in the yield. Therefore, the irrigation lower limit of the relative soil moisture of 70% was suggested for the wide ridge furrow irrigation and conventional furrow irrigation where water resource was abundant. If water resource was scarce, the irrigation lower limit of the relative soil moisture of 60% was recommended for the conventional furrow irrigation. In sum, the study showed that the improve fuzzy comprehensive evaluation was good for assessment of effects of water saving irrigation.