Can soil organic carbon sequestration and the carbon management index be improved by changing the film mulching methods in the semiarid region?
Jialin Yang, Liangqi Ren, Nanhai Zhang, Enke Liu, Shikun Sun, Xiaolong Ren, Zhikuan Jia, Ting Wei, Peng Zhang
Abstract
Plastic-film mulching has been widely used to increase maize yield in the semiarid area of China. However, whether long-term plastic-film mulching is conducive to agricultural sustainability in this region remains controversial. A field experiments was stared in 2013 with different film mulching methods, including (i) a control method, flat planting without mulching (CK), (ii) flat planting with half film mulching (P), (iii) film mulching on ridges and planting in narrow furrows (S), (iv) full film mulching on double ridges (D), and (v) film mulching on ridges and planting in wide furrows (R). In order to evaluated the effects on soil organic carbon (SOC) content, storage, fractions and carbon management index (CMI) after nine consecutive years of plastic-film mulching. The results showed that long-term plastic-film mulching generally maintained the initial SOC level. Compared with no mulching, plastic-film mulching average increased crop yield, biomass yield, and root biomass by 48.38, 35.06, and 37.32%, respectively, which led to the improvement of SOC sequestration. Specifically, plastic film-mulching significantly improved CMI, and increased 13.59% SOC content, 7.47% SOC storage and 13.78% easily oxidizable organic carbon (EOC) on average, but decreased other labile fractions. SOC sequestration and CMI were improved by changing plastic film-mulching methods, and S treatment had the best effect among the four mulching methods, so it could be used as a reasonable film-mulching method for sustainable agricultural development in semiarid area.