Abstract:

In order to investigate the response of yield and quality of spring maize to changes in moisture and heat, a sowing experiment was carried out in Xifeng, Gansu Province. The characteristics of growth, development, yield and quality of spring maize under different sowing dates were analyzed. The results showed that with the delay of sowing date, the length of development period of spring maize shortened, timely early sowing could make full use of climate resources to increase the process of material accumulation; leaf area index, dry matter accumulation and yield components changed greatly in different sowing dates, and were closely related to the matching degree of hydrothermal resources; the growth rate of dry matter weight had the characteristics of slow-fast-slow, the growth rate before seven-leaf stage was slow, accelerated from jointing to milk-ripening, and decreased after milk-ripening, there was a significant difference in dry matter quality between tasseling-milk ripe, milk ripe-mature; the effect of sowing date on essential amino acids, semi-essential amino acids, non-essential amino acids, protein, fat and crude fiber of spring maize was not obvious. The study found that meteorological factors have a direct impact on the quality of maize. According to the climate year type, the suitable sowing date of maize is selected, so that the grain filling period is under superior light and heat conditions, and the effects of frost and drought can be avoided. Maize can achieve high yield. The normal or more precipitation in March to early April in spring is suitable for early sowing, and the most suitable sowing period is April 20-25. The less precipitation in March to early April in spring is suitable for late sowing, and the most suitable sowing period is April 25-May 5. The study provides a reference for dryland maize in the northwest Loess Plateau to cope with climate change.

Key words: spring corn, sowing date, Loess Plateau, yield, quality, Longdong region