Influence of climate change and mechanized harvesting on maize (Zea mays L.) planting and northern limits in northeast China.

BACKGROUND

Northeast China is one of the most important maize producing areas in China. Due to limitations on crop growth resulting from temperature, whether this area can realize mechanical kernel harvesting maize (MKHM) will directly affect the stable development of maize in the region. The effects of climate change on the northern limits of early maturing MKHM were also analyzed in the study.

RESULTS

The mean temperature during the maize growth period increased at a rate of 0.22 °C/10a from 1960 to 2018. The average growth periods for early, middle- and late-maturing common harvest maize (CHM) were 123, 135, and 140 days, respectively, and the accumulated temperature above 10 °C (AAT10) was 2400 °C, 2800 °C, and 3100 °C. The early maturing MKHM growth period was about 20 days longer than that of early maturing CHM, and thus the AAT10 of the MKHM was 2700 °C. From 2000-2018, the northern limits for the early maturing CHM maize planting were located from south of Nenjiang and Wudalianchi (47° 98' N-49° 74' N), while the northern limits for the early maturing MKHM maize were located in south Keshan, Nehe, and Hailun (46° 32' N-48° 70' N), which was about 148 km southward compared to the northern limits of the early maturing CHM maize.

CONCLUSION

This study not only confirmed the northern limits of early maturing MKHM maize but also indicated that the development of MKHM offsets the influences of climate change on the northern limits of maize planting. This is very important for the sustainable development of maize in the region. © 2020 Society of Chemical Industry.