DESCRIPTIVE STUDY OF THE CAPACITY OF SIX HILLSIDE SOIL MANAGEMENT SYSTEMS IN THE CONTROL OF SURFACE RUNOFF

On tropical hillsides, torrential rains cause surface runoff that removes soil particles, nutrients and agro-inputs. This process limits soil fertility, agrosystem productivity and the rural economy. A descriptive study was conducted on a hillside in Los Tuxtlas, Veracruz, Mexico, to study water runoff and its runoff coefficients in four modalities of the “milpa intercropped with fruit trees” (MIAF) system, traditional and zero tillage, under rainfed conditions. The systems were established with a systematic design of treatments, without repetitions, between 2003 and 2011: 1) Milpa intercropped in chicozapote (Manilkara zapota), with sediment filter and minimum tillage (MIAF-CH-CF-LM); 2) Milpa intercropped with Persian lemon (Citrus x latifolia), with sediment filter and minimum tillage (MIAF-L-CF-LM); 3) Milpa intercropped in carambolo (Averrhoa carambola), with sediment filter and minimum tillage (MIAF-C-CF-LM); 4) Milpa intercropped in carambolo, without sediment filter and zero tillage (MIAF-C-SF-L0); 5) Zero tillage with crop residue distribution over the surface (Lo); and 6) Minimum tillage with crop residue burning and tracking (LM-QR). From August 2016 to February 2018, a 50 m2 runoff lot was installed in each system. Surface runoff was measured every 24 h; runoff sheet and runoff coefficient. The MIAF.system reduced surface runoff by 46.13 % with respect to that obtained in LM-QR. The MIAF systems with sediment filter and zero tillage without filter presented similar runoff and runoff coefficient values. The MIAF-CH-CF-LM system recorded the lowest runoff value among systems with tillage and filter. The L0 system showed the lowest volume and runoff coefficient.