Impact of direct sowing mulch-based cropping systems on soil carbon, soil erosion and maize yield

Abstract

-We studied the impact of direct seeding mulch-based cropping systems (DMC) on soil characteristics and maize production compared with conventional tillage management (CT) in the semi-arid region of western Mexico. Mulch treatments included 0, 1.5, 3 and 4.5 Mg ha -1 of added surface crop residues. The study was carried out from 1994 to 1998 on a Dystric Cambisol soil in La Tinaja in the state of Jalisco. Water runoff, soil erosion, soil C changes, maize aboveground biomass and grain yield were monitored on field plots. The results show that mulch treatments reduced annual water runoff losses by 10 to 50% relative to the conventional tillage treatment depending on residue amounts, slope and year. Soil erosion losses were reduced by 50 to 90%. Over a 5-year period soil carbon levels under mulch increased by 23 to 29% compared with conventional tillage, mainly due to increased crop residue inputs and reduced soil carbon erosion under mulch treatment. In the year with the most intense rainfall (1997), the conventional treatment lost about 800 kg of C ha -1 i.e. 2 to 7 times greater than mulch treatments. Maize grain yields were greater by 170 to 190% under mulch. Yield increases under mulch occurred each year, notably due to improved water and nutrient use efficiency. Potential yield benefits under mulch in the longer term due to build-up of soil organic matter and reduction of soil erosion were not obvious in our experiment. Overall, even small amounts of surface residue are effective at sustaining rainfed maize productivity under the semi-arid conditions of western Mexico. The short-term yield benefits are a promising factor for adoption of direct seeding mulch-based systems in the region. direct sowing / mulch / runoff / erosion / soil organic carbon / Mexico

Soils and food sufficiency. A review

“…In El Batan, Mexico, Govaerts et al (2006Govaerts et al ( , 2007 observed that NT farming with crop residue mulch was essential to enhancing SOM and improving soil quality. In western Mexico, Scopel et al (2005) also observed significant yield benefits of growing NT maize under the semi-arid conditions. In southern Brazil, De Bona et al (2006) observed that NT farming along with high input systems are needed to counter-balance the higher SOM decomposition rates in a sub-tropical Acrisol.…”

“…Similar positive effects on crop growth and yields have been reported with regards to the use of conservation tillage and mulching. Long-term effects of no-till (NT) farming in conjunction with crop residue mulch are due to improvements in SOM and decrease in soil erosion (Scopel et al, 2005). Effects of accelerated erosion on trends in crop growth and yield in intensively managed soils under commercial farming practices are similar to those of the tropics, but the magnitude of the adverse effects on crop yield is small (den Biggelaar et al, 2003a, b).…”

Mixing Plant Species in Cropping Systems: Concepts, Tools and Models: A Review

“…(iv) Multispecies systems can sequester carbon over pure crop stands. Trees and/or cover crops (Vandermeer et al, 1998;Scopel et al, 2005) may also enhance the soil carbon content, thus participating in climate change mitigation.…”

Cotton expansion and biodiversity loss in African savannahs, opportunities and challenges for conservation agriculture: a review paper based on two case studies

“…) can be effective in reducing water loss, soil erosion and increasing yield (Scopel et al 2004(Scopel et al , 2005. Maintaining a mulch of crop residues through the growing season also makes rotation necessary as residues may carry diseases or pests from the previous crop.…”