NITROGEN AND ORGANIC MATTER LOSSES IN NO‐TILL CORN CROPPING SYSTEMS¹

Abstract

Intensive cropping systems based on mechanical movement of soil have induced land degradation in most agricultural areas due to soil erosion and soil fertility losses. Thus, farmers have been increasing fertilization rates to maintain an economically competitive crop yield. This practice has resulted in water quality degradation and lake eutrophication in many agricultural watersheds. Research was conducted in the Patzcuaro watershed in central Mexico to develop appropriate technology that prevents nonpoint source pollution from fertilizers. Organic matter (OM) and nitrogen (N) losses in runoff and nitrate (NO3‐N) percolation in Andisols with corn under conventional till (CT) and no‐till (NT) treatments using variable percentages of crop residue as soil cover were investigated for steep‐slope agriculture. USLE type runoff plots were used to collect water runoff, while suction tubes with porous caps at 30, 60, and 90 cm depth were used to sample soil water solutes for NO3‐N analyses. Results indicated a significant reduction of N and OM losses in runoff as residue cover increased in the NT treatments. Inorganic N in runoff was 25 kg/ha for NT without residue cover (NT‐0) and 6 kg/ha for the NT with 100 percent residue cover (NT‐100). Organic matter losses in runoff were 157 and 24 kg/ha for the NT‐0 and NT‐100 treatments, respectively. Nitrate‐N percolation was evident in CT and NT with 100 percent residue cover (NT‐100). However, NT‐100 had higher NO3‐N concentration at the root zone, suggesting the possibility of reducing fertilization rates with the use of NT treatments.

NPS Pollution Reduction from Alpine Fields using Surface Cover Material and Soil Amendments

“…For example, no-till cultivation using crop residue cover reduced runoff velocity and increased infiltration (Locke, 2008). Tiscareno-Lopez et al (2004) reported that the no-ploughing agricultural method (leaving the land covered with the crop residue) reduced runoff at their sites (on 9% slope, similar to the present study) by 46-77% against that from the control plot. Won et al (2012a) showed that the reduction of runoff ratio ranged from 70% to 80% under simulated rainfall (10% slope and 30 mm/h rainfall intensity) and the same surface cover and soil amendments (SPG) as used in the present study.…”

Diffuse Pollution Swapping in Arable Agricultural Systems

“…Losses of total organic carbon in leachate were found to increase with the amount of corn residue applied (147). However, Tiscareno-Lopez et al (182) found that total organic matter in runoff was reduced by 85% as corn residue cover was increased from zero to 100%. The reduction in carbon lost was primarily due to a reduction in the volume of runoff produced.…”

Diagnosis for ecological intensification of maize-based smallholder farming systems in the Costa Chica, Mexico

“…It has been demonstrated that residue retention provides protection from raindrop impact, and causes an increase in soil roughness reducing the runoff flow velocity and flow transport capacity. This also limits evaporation and is thereby increasing the amount of water available for plant uptake (Gilley et al 1987;Fowler and Rockstrom 2001;Hartkamp 2002;Tiscareño et al 2004). As a rule of thumb, 30% ground cover is recommended by various authors (Lal, 1976;Uri and Lewis 1999;Scopel et al 2004;Tiscareño et al 2004).…”

“…This also limits evaporation and is thereby increasing the amount of water available for plant uptake (Gilley et al 1987;Fowler and Rockstrom 2001;Hartkamp 2002;Tiscareño et al 2004). As a rule of thumb, 30% ground cover is recommended by various authors (Lal, 1976;Uri and Lewis 1999;Scopel et al 2004;Tiscareño et al 2004). More knowledge on the relation between ground cover and erosion is needed to understand the trade-off between crop residues for animal feed and for soil protection.…”