AUTHOR=Tian Rongrong , Qi Guangping , Kang Yanxia , Jia Qiong , Wang Jinghai , Xiao Feng , Gao Yalin , Wang Chen , Lu Qiang , Chen Qidong 

TITLE=Effects of irrigation and nitrogen application on soil water and nitrogen distribution and water-nitrogen utilization of wolfberry in the Yellow River Irrigation Region of Gansu Province, China

JOURNAL=Frontiers in Plant Science

VOLUME=Volume 14 - 2023

YEAR=2023

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2023.1309219

DOI=10.3389/fpls.2023.1309219

ISSN=1664-462X

ABSTRACT=To address the problems of extensive field management, low productivity, and inefficient water and fertilizer utilization in wolfberry (Lycium barbarum L.) production, an appropriate water and nitrogen regulation model was explored to promote the healthy and sustainable development of the wolfberry industry. Based on a field experiment conducted from 2021 to 2022, four irrigation levels [75%–85% θf (W0), 65%–75% θf (W1), 55%–65% θf (W2), and 45%–55% θf (W3)] and four nitrogen application levels [0 kg·ha−1 (N0), 150 kg·ha−1 (N1), 300 kg·ha−1 (N2), and 450 kg·ha−1 (N3)]. The results showed that the soil moisture content of the 40–80 cm soil layer was higher than those of 0-40 cm and 80-120 cm soil layer. The NO3−–N content in the 0–80 cm soil layer was more sensitive to water and nitrogen regulation, and the cumulative amount of NO3−–N in the soil followed the order of W0 > W1> W2 > W3 and N3 > N2 > N1 > N0 during the vegetative growth period. The yield of wolfberry under the W1N2 treatment was the highest (2623.09 kg·ha−1), which was 18.04% higher than that under the W0N3 treatment. The water use efficiency reached a peak value of 6.83 kg·ha−1·mm−16.83 kg·m−3 under the W1N2 treatment. The nitrogen uptake of fruit and nitrogen fertilizer recovery efficiency of fruit first increased and then decreased with increasing irrigation and nitrogen application. The treatment of W1N2 obtained the highest nitrogen uptake of fruit and nitrogen recovery efficiency of fruit, which were 63.56 kg·ha−1 and 8.17%, respectively. Regression analysis showed that the yield and water-nitrogen use efficiency of wolfberry improved when the irrigation amount ranged from 315.4 to 374.3 mm, combined with nitrogen application amounts of 300.0 to 308.3 kg·ha−1. Additionally, the soil NO3−–N residue was reduced, making it an optimal water and nitrogen management model for wolfberry planting. The present findings contribute novel insights into the production of wolfberry with saving water and reducing nitrogen, which helps to improve the level of wolfberry productivity in the Yellow River irrigation region of Gansu Province and other areas with similar climate.