Broad-row ridge culture improving photosynthetic characteristics and lodging resistance, and increasing yield of summer maize with waterlogging at seedlings stage

Abstract: To better understand the effects of broad-row ridge culture pattern on photosynthetic characteristics, lodging resistance and yield for summer maize waterlogged at seedlings stage, an experiment was conducted in the Institute of Agriculture Science in Funan County in 2013 and 2014. A summer maize cultivar, Xianyu-335, was selected as material in the field, and 4 treatments were designed including traditional culture without waterlogging (TW0), traditional culture with waterlogging (TW1), broad-row ridge culture without waterlogging (RW0) and broad-row ridge culture with waterlogging (RW1). The results showed that the date of SPAD (soil and plant analyzer development) value and photosynthesis rate of the maize functional leaf recovering to normal level under broad-row ridge culture was 10 days earlier than that under traditional culture in waterlogging year. Therefore, the photosynthetic capacity was more quickly meliorated under broad-row ridge culture than that under traditional culture when a flood occurred. The leaf area of maize recovered to normal level 15 days after waterlogging under broad-row ridge culture in waterlogging year, but couldn't recover to normal level even 30 days after waterlogging under traditional culture. Thus, a larger green photosynthetic leaf area was provided under broad-row ridge culture than under traditional culture when in waterlogging year. The lodging resistance indicators in the third internode of maize such as stem diameter, stalk rind penetration strength and bending property in waterlogging year were worse than those in normal years under traditional culture, with a reduction rate of 20.1%, 16.1% and 20.0%, respectively. There was no significant difference for the lodging resistance capability between the 2 treatments with or without waterlogging under broad-row ridge culture. The lodging resistance capability for the 2 planting patterns had no significant difference under the same water-type years. Collectively, the capability of lodging resistance under broad-row ridge culture was more reliable than that under traditional culture. Sterile plant rate and 1 000 grain weight under broad-row ridge culture were significantly (P<0.05) lower than those under traditional culture in waterlogging year, with a decline of 21.5% and 5.7%, respectively. The number of grains per ear in maize in waterlogging treatment was significantly (P<0.05) less than that in no-waterlogging treatment under traditional culture, with a two-year average reducing rate of 11.3%, but it had no significant difference between the 2 different water-type treatments under broad-row ridge culture. So, more stable number of grains per ear was gained under broad-row ridge culture. The yield in waterlogging year was significantly (P<0.05) lower than that in no-waterlogging year, with a reduction of 1349.6 and 547.3 kg/hm2 respectively for the 2 planting patterns, but the yield under broad-row ridge culture was not lower than that under traditional culture whether waterlogging or not. Therefore, a more stable yield was obtained under broad-row ridge culture in the areas liable to waterlogging. The research provides the reference for the high and stable yield theory and technology of summer maize in the areas liable to waterlogging.