Accordingly, CA in China may benefit mainly maize cropping for high yield. In the present study, the effects of CA on crop yield were significantly different among specific practices, regional climates, and crop types. Similarly, recent studies have also shown that impacts
of Selleckchem Trichostatin A CA on crop yield could be positive or negative. For example, positive effects of CA on crop yield were observed in the U.S., Australia, India, and Canada ,  and . However, negative effects were observed in Europe . DeFelice et al.  also reported that there were large variations in CA effects on crop yield between cropping regions in the U.S. and Canada. To avoid negative impacts of CA on crop productivity, specific CA practices should be used in specific regions and crops. No significant effect of NT on crop yield was found in China (Fig. 2). Rusinamhodzi et al.  found that NT had no significant effect on maize yield under rainfed conditions. Putte et al.  also showed that the introduction of NT in Europe may indeed have exerted negative effects and had reduced crop yield by an average of 8.5%. Continuous NT decreased crop yield in North China (Fig. 3), probably owing to the high precipitation. Wang et al.  also showed that NT was a promising
practice only in low-precipitation BMS-354825 clinical trial conditions in northern China. However, continuous NT was not recommended and NT showed more prominent benefits when combined with residue retention than did NT alone . NT with crop residue mulching can not only markedly improve soil moisture conditions, but also increase organic
carbon and nutrient inputs into the soil . Thus, it would be better to apply NT plus straw mulching to avoid potential negative effects of NT on crop yield. Among the CA methods applied in China, straw retention (CTSR and NTSR) showed a significant positive effect on crop yield (Fig. 2). Generally, straw retention improves aggregate stability, reduces soil erosion, and increases the infiltration and conservation of soil water, thus enhancing soil productivity ,  and . Additionally, straw retention directly increases the input of organic matter and nutrients into soil, in turn improving soil nutrient availability for crop growth ,  and . On the other hand, straw retention may cause poor crop germination by reducing soil CYTH4 temperature and excessively increasing soil moisture, resulting in reductions in crop yield ,  and . In addition, straw retention may depress crop growth by nutrient immobilization in soil microbes and increases in residue-borne diseases ,  and . However, despite the potential negative effects of straw retention on crop growth, the benefits derived from improved soil fertility and water availability may offset the negative factors  and . In this study, there were significant differences in the effect sizes of straw retention among cropping regions (Fig. 3).