Clearfield upland rice intercropped with Urochloa ruziziensis for grain, increased revenue and environmental preservation

• Published in: Agronomy journal 2024-07, Vol.116 (4), p.1917-1932
• Main Authors: Sousa Santos, Fenelon Lourenço, Nascente, Adriano Stephan, Lacerda, Mabio Chisley, Calil, Francine Neves
• Format: Article
• Language: English
• Subjects: agronomy; Brazil; continuous cropping; costs and returns; crude protein; cultivars; dry matter accumulation; forage grasses; grain yield; highlands; imazapic; imazapyr; income; intercropping; Oryza sativa; pastures; profitability; rice; soil; sowing; Urochloa ruziziensis
• ISSN: 0002-1962; 1435-0645
• DOI: 10.1002/agj2.21576

Intercropping perennial forage grasses into cereal crops is an alternative to recover degraded pastures. However, the intercrop of forage grasses, such as Urochloa ruziziensis (R. Germ. and C. M. Evard) Crins (Congo grass), can lead to losses in cereal yield. Therefore, it is necessary to develop management strategies that allow forage grass establishment without major losses in cereal yield in intercropping. The objective was to study the agronomic and economic impacts of intercropping U. ruziziensis into a Clearfield upland rice (Oryza sativa L.) cultivar in the state of Goiás, Brazil, in two growing seasons. Treatments included forage grass seeds sowing method (broadcast or incorporation to the soil) and sowing times (at rice sowing, 20 days after emergence [DAE], and 45 DAE of rice). Also, imazapyr + imazapic herbicide was applied to restrict the competitive effect on rice yield. Monocropping control plots were also evaluated. Grain yield was measured on rice. Forage grass dry matter yield was measured at 30, 60, and 90 days after harvesting (DAH) of rice. Crude protein content was analyzed at 90 DAH. Profitability was calculated for each cropping system relative to rice monocropping. Intercropping of rice and U. ruziziensis sowed at 45 DAE provided the highest grain yield relative to other assessed intercropping treatments as well as rice monocropping. Concurrent sowing of rice and incorporated U. ruziziensis seeding provided the greatest economic return. This reformed cropping system improved land and pasture output, which can reduce the pressure to convert more land to agricultural use. Core Ideas The use of herbicide‐resistant rice makes intercropping with forage plants feasible for pasture renewal. Intercropping management with imazapyr + imazapic does not affect rice yield. Intercropping rice with Urochloa ruziziensis increases land use capacity. The intercropping of rice and U. ruziziensis reduces the environmental and social pressure to deforest new areas.