Abstract:

The aim of this study is to clarify the impact of intercropping on crop yield, and to provide a theoretical basis for the rational application and promotion of intercropping measures. This study used a single cropping as a control to quantify and analyze the effects of intercropping on crop yield and the influencing factors. The results showed that, compared with single cropping, intercropping significantly reduced crop yields, especially in temperate regions. In addition, intercropping also reduced crop yields under ground cover and legume conditions. However, when rainfall exceeded 600 mm, crop yield of intercropping significantly increased by 29.6%, compared with single cropping. When rainfall was less than 600 mm, crop yield of intercropping decreased by 18.7%. The average annual temperature also significantly affected the yield effect of intercropping. When the annual average temperature was higher than 20℃, the crop yield of intercropping was reduced by 55.1%, compared with single cropping. Long-term intercropping (>5 years) was conducive to yield increase, but when the number of years was less than 3 years, crop yield of intercropping decreased compared with single crop. Under high organic matter content (>20 g/kg) and low organic matter content (<1 g/kg), intercropping was not conducive to crop yield increase. Similarly, when the total nitrogen in soil was higher than 1.5 g/kg, crop yield of intercropping was reduced by 48.6%. The yield reduction of intercropping was the greatest at pH 6.5-7.5. When the available phosphorus, nitrogen, and potassium contents in soil were >30 mg/kg, <50 mg/kg, and 50-100 mg/kg, respectively, intercropping reduced crop yield compared with single cropping. Therefore, the yield effect of intercropping is affected by various factors such as climate, test years and soil properties.

Key words: intercropping, crop yield, experimental duration, Meta-analysis