Objective  Effects of intercropping peanut (also as green fertilizer) on soil and microclimate at banana orchards were studied.

  Method  Five different planting practices at a banana orchard were implemented for comparison. They included CK (banana monoculture as control), Method A (3 rows of 2-peanuts-sowing for intercropping with banana followed by mulching with the plant waste), Method B (3 rows of 2-peanut-sowing for intercropping with banana followed by turning the plant waste into field soil), Method C (5 rows of one-peanut-sowing for intercropping with banana followed by mulching with the plant waste), and Method D (5 rows of one-peanut-sowing for intercropping with banana followed by turning the plant waste into field soil). Effects of the various seeding/waste treatments on the physiochemical properties of soil and microclimate at the orchard as well as the banana/peanut yields and quality were determined.

  Result  Method C was found to perform with the highest scores on the major evaluation criteria among all. The banana seedling height, stem circumference and green leaf count were 89.74%, 11.89% and 32.05%, respectively, greater than those under CK. With respect to the microclimate, Method C increased the surface humidity by 4.61%, decreased the ground temperature by 2.07%, and lowered the air temperature by 8.39%, as compared with CK. Furthermore, it also reduced the weed growth by 84.62% and the banana plant damage rate by 65.21%. The contents of available N, P, K, Ca, and Mg in the orchard soil were significantly increased by 17.18%, 6.17%, 76.01%, 63.58%, and 34.59%, respectively, while the organic matters significantly increased by 25.15% under Method C over CK. Among the enzymes in the soil, the activity of invertase was 2.38 times of that under CK at an extremely significant different level; and, those of urease, acid phosphatase, catalase, and cellulase 44.27%, 75.92%, 13.94%, and 11.58%, respectively, higher than those under CK. Method C also resulted in a rise on the percent soil aggregates with a size larger than 2mm from 22.0% under CK to 35.22%. Moreover, the treatment produced bananas with increases on yield of 2.31%, on soluble sugar of 15.21%, on VC of 5.10%, and on soluble solids of 8.73%.

  Conclusion  It appeared that by intercropping banana plants with peanut bushes followed by mulching the ground with peanut plant wastes could significantly improve the structure, fertility, and enzymatic activities of the soil as well as the microclimatic conditions, such as temperature and humidity, at the orchard. In the end, besides the ecological benefits, the practice would promote the banana growth, reduce the pest infestation, and weed proliferation, as well as improve the crop yield and quality for the orchard operation.