2013 Volume 5 Issue 2 Pages 46-58
Living mulch with low-grade wheat grain can develop higher wheat seeding rates with low seed cost and prevents the growth of weeds in the early stages. Many reports of wheat living mulch have pointed out specific aspects such as weed suppression and insect pest control, but few have focused on its multifunctional aspects in farm experiments. This study focuses on the synthetic aspect of the effect of using living mulch with low-grade wheat grains on cultivated field ecosystems. We evaluated the cultivated field ecosystem for above-ground vegetation (weed suppression), soil chemical properties (nitrogen dynamics), soil physical properties (soil hardness), and soil biological properties (soil nematode community).
A field investigation was conducted on June 5, June 26, and September 13, 2012 in Kinoshijuku in Nasu- Karasuyama, Tochigi, Japan. In a living mulch plot, 75 kg/10a of low-grade wheat was sown as living mulch, which exceeded the usual seeding density. In the living mulch plot, the mulch covered the soil surface in early stages and greatly suppressed weed growth from 3.3% to 17.8%, compared to a fallow plot. In addition, nitrogen accumulation by living mulch greatly reduced nitrate leaching from 12.1% to 40.3% in June; however, soil nitrate was 24.3 kgN/10a higher in the living mulch plot than in the fallow plot. Furthermore, soil physical properties, such as soil porosity and soil hardness, improved because of soil structure formation by root decomposition. Living mulch affected soil nematodes community, however, the effects were not significant.
These results suggested that using living mulch with low-grade wheat exerts a strong impact on cultivated field ecosystems with respect to above-ground vegetation, soil chemical properties, soil physical properties, and soil biological properties; it leads to weed suppression, improved soil hardness, and reduced nitrate leaching. This farming system may thus work as one of the appropriate organic farming techniques that can ensure crop productivity and environmental quality at the same time.
