Increased photosynthesis and grain yields in maize grown with less irrigation water combined with density adjustment in semiarid regions

PeerJ

article

Donghua Liu¹  Qianmin Jia⁴  Juan Li¹  Peng Zhang¹  Xiaolong Ren¹  Zhikuan Jia¹ 

[1] College of Agronomy, Northwest A&F University;Institute of Water Saving Agriculture in Arid Areas of China, Northwest A&F University;Key Laboratory of Crop Physi-ecology and Tillage Science in North-western Loess Plateau, Ministry of Agriculture, Northwest A&F University;State Key Laboratory of Grassland Agro-Ecosystems, Key Laboratory of Grassland Livestock Industry Innovation, Ministry of Agriculture, China, College of Pastoral Agriculture Science and Technology, Lanzhou University

关键词: Rainfall harvesting;    Net photosynthetic rate;    Supplemental irrigation;    Climate change;    Density;   

DOI  :  10.7717/peerj.9959

学科分类：社会科学、人文和艺术（综合）

来源: Inra

【 摘 要 】

In order to design a water-saving and high-yield maize planting model suitable for semiarid areas, we conducted trials by combining supplementary irrigation with different planting densities. Three planting densities (L: 52,500, M: 75,000, and H: 97,500 plants ha–1) and four supplementary irrigation modes (NI: no irrigation; IV: 375 m3 ha–1 during the 11-leaf stage; IS: 375 m3 ha–1 in the silking stage; and IVS: 375 m3 ha–1 during both stages) were tested. The irrigation treatments significantly increased the leaf relative water content, but the high planting density significantly decreased the relative water content during the silking and filling stages. After supplementary irrigation during the 11-leaf stage, IV and IVS significantly increased the photosynthetic capacity, but decreased the leaf water use efficiency. IS and IVS significantly increased the photosynthetic capacity after supplementary irrigation in the silking stage over two years. During the filling stage, IV, IS, and IVS increased the two-year average net photosynthetic rate by 17.0%, 27.2%, and 30.3%, respectively. The intercellular CO2 concentration increased as the density increased, whereas the stomatal conductance, transpiration rate, net photosynthetic rate, and leaf water use efficiency decreased, and the high planting density significantly reduced the leaf photosynthetic capacity. The highest grain yield was obtained using the IVS treatment under the medium planting density, but it did not differ significantly from that with the IS treatment. Furthermore, the IVS treatment used two times more water than the IS treatment. Thus, the medium planting density combined with supplementary irrigation during the silking stage was identified as a suitable water-saving planting model to improve the photosynthetic capacity and grain yield, and to cope with drought and water shortages in semiarid regions.

【 授权许可】

CC BY