Long-term no-till integrated crop-pasture system as a strategy to enhanced rainwater productivity, food production stability, and profitability

Sustainable intensification in tropical agriculture requires production systems that improve soil fertility, stabilize yields, enhance rainwater use, and increase farm profitability over the long term. However, integrated evidence from long-term tropical no-till experiments remains scarce. This study evaluated the effects of four off-season strategies within a 12-year field experiment in Brazil (2006-2018): fallow, second crop, cover crop, and forage grass-based systems under no-till management. The experiment was conducted in a randomized complete block design with four replications. Soil chemical attributes were measured to 0.60 m depth in 2006 and 2018, while grain yield was assessed in all growing seasons from 2006/2007 to 2017/2018. Apparent rainwater productivity, yield stability, estimated animal stocking rate, meat production, and economic return were also determined. The systems differed consistently in agronomic, soil, and economic performance. Across soil parameters, the forage system outperformed all others; relative to fallow, it increased soil P, K, Ca, and Mg by 65%, 71%, 82%, and 86%, respectively, and reduced Al saturation by 52%. Grain yield followed the same ranking, with forage > second crop > cover crop > fallow. In the most recent season of each crop, soybean, maize, rice, and common bean yields were 1.51, 3.17, 0.83, and 0.93 Mg ha-1 higher, respectively, in the forage system than in the fallow system. When both spring-summer and fall-winter production were considered, the second crop system had the highest apparent rainwater productivity, exceeding the average of the other systems by 8.3 kg grain mm-1. The forage system also generated the highest economic return. Over 12 years, total net income reached US$12,803 in the forage system, compared with US$8,720 in the second crop system, US$7,131 in the cover crop system, and US$4,948 in the fallow system. These results show that, under tropical no-till conditions, replacing fallow with biologically active off-season systems, especially forage grasses integrated with livestock potential, simultaneously improves soil fertility, production stability, rainwater use, and profitability.