Conservation agriculture improves yield and reduces weeding activity in sandy soils of Cambodia

Abstract

The years of intensive tillage in Cambodia have caused significant decline in agriculture’s natural resources that could threaten its future of agricultural production and sustainability. Conventional tillage could cause rapid loss of soil organic matter, leading to a high potential for soil degradation and decline of environmental quality. Hence, a better and comprehensive process-based understanding of differential effects of tillage systems and crop management on crop yield is critically needed. A study was conducted in 10 farmer’s fields to evaluate the effect of conservation agriculture and conventional tillage on yield of selected crops and weeding activity in two villages of Siem Reap, Cambodia. The experiment was laid out following a 2 × 2 factorial treatment combination in randomized complete block design. Each treatment was replicated five times. Each farmer’s field was divided into four plots and was randomly assigned with production management and irrigation treatments, respectively. We demonstrated that our results supported the overall premises of conservation agriculture. Average yields of selected crops were significantly (≤ 0.001) improved in plots with conservation agriculture (17.1 ± 6.3 to 89.3 ± 40.2 Mg ha−1) compared with conventional tillage (18.8 ± 6.4 to 63.8 ± 27.7 Mg ha−1). Our results showed that manual weeding in all cropping seasons was significantly reduced by about 35% in conservation agriculture (169 ± 23 to 125 ± 18 man-day ha−1), which can be attributed to existing cover crops and surface mulch. Overall, our results suggest that in smallholder commercial household farms, adoption of conservation agriculture had a profitable production management system, which could save natural resources, improve yield, and reduce labor. We proved for the first time that in Cambodian smallholder commercial household farms, adoption of conservation agriculture saves natural resources, improves yield, and reduces labor. Additional studies are encouraged to further test the conservation agriculture system for a longer period of time, with repeated cropping sequences.