Abstract
In order to increase crop yield in semi-arid and arid areas, plastic film mulching (PFM) is widely used in Northwestern China. To date, many studies have addressed the effects of PFM on soil physical and biochemical properties in rain-fed agriculture in Northwestern China, but the findings of different studies are often contradictory. Therefore, a comprehensive review of the impacts of PFM on soil water content, soil nutrients and food production is needed. We compiled the results of 1278 observations to evaluate the overall effects of PFM on soil water content, the distribution of nitrate and soil organic carbon, and crop yield in rain-fed agriculture in Northwestern China. Our results showed that PFM increased soil moisture and nitrate concentration in topsoils (0–20 cm) by 12.9% and 28.2%, respectively, but slightly decreased (1.8%) soil organic carbon (SOC) content in the 0–10 cm soil layer. PFM significantly increased grain yields by 43.1%, with greatest effect in spring maize (79.4%). When related to cumulative precipitation during the crop growing season, yield increase from PFM was greatest (72.8%) at 200–300 mm, which was attributed to the large increase for spring maize and potato, implying that crop zoning would be beneficial for PFM in this region. When related to N application rate, crop yields benefited most from PFM (80.2%) at 200–300 kg/ha. A cost-benefit analysis indicated that PFM increased economic return by an average of 29.5%, with the best improvement for spring maize (71.1%) and no increase for spring wheat. In conclusion, PFM can significantly increase crop yield and economic return (especially for spring maize) in rain-fed agriculture areas of Northwestern China. Crop zoning is recommended for PFM to achieve the largest economic benefit. However, full account needs to be taken of the environmental impacts relating to N loss, SOC depletion and film pollution to evaluate the sustainability of PFM systems and further research is required to quantify and mitigate these impacts.
Highlights
As the human population increases, the global demand for food is expected to double by 2050 (Tilman et al, 2012)
Some studies have suggested that the mechanism for yield increase under plastic film mulching (PFM) is an improvement in soil water and temperature conditions and an enhancement of soil nutrient availability; associated with the consumption of soil organic carbon (Wilson and Jefferies, 1996; Gao et al, 2009)
The following five criteria were defined for a study to be included in the analysis: i) the field experiment and the experimental sites were located in rain-fed agriculture areas of Northwestern China (Shaanxi; Gansu; Qinghai; Xinjiang; northwest Inner Mongolia); ii) the crop grain was harvested at the physiological mature stage; iii) in addition to the treatment; a control group without the application of PFM was included in the experiment design; iv) reported averages of observational data were based on at least three replicates; v) the application rates of nutrient inputs were reported; for inclusion in the cost–benefit analysis
Summary
As the human population increases, the global demand for food is expected to double by 2050 (Tilman et al, 2012). On the other hand, Liu et al (2014) and Gao et al (2014) reported that PFM increased crop root growth and root exudates, promoting soil organic carbon accumulation These differences could be related to different crops with different root systems, differences in the number of years that mulching has been practiced (short vs long-term) or different management practices (i.e. high N input could stimulate soil organic matter mineralization). The effects of PFM on crop yields and agricultural ecosystems are variable, considering the different factors, such as climate (precipitation and temperature), crops, soils, and agricultural management practices (e.g. N input levels), and a comprehensive assessment based on all available data is needed to evaluate the economic and environmental sustainability of the practice for arid and semiarid regions
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
