Configurações, densidades e orientações de cultivos em sistemas biossalinos de consórcios palma-sorgo

Abstract

The edaphoclimatic conditions of the semiarid regions, together with the increase in demand for forage, due to the growth of herds and greater demands for products of animal origin (i.e., milk and meat), refer to the need for improvement in cultivation conditions through strategies mitigating factors, with an emphasis on the use of agricultural resilience practices. Among them, we can highlight the use of adapted species (e.g., forage cactus and sorghum), diversification in the productive system, use of efficient irrigation, biosalin agriculture, ideal plant density and cultivation guidance in an appropriate way. However, there is little research on the forage cactus-sorghum consortium under irrigation with saline water, submitted to different cultivation configurations, density and planting orientation. That said, the objective was to evaluate the productive responses, economic benefits, morpho-phenological indices of the forage cactus-sorghum consortium grown under different strategies to improve agricultural resilience. The research was conducted in the period from 2018 to 2020 at the International Reference Center for Agrometeorological Studies of Palma and other Forage Plants - Centro REF, located in Serra Talhada, Pernambuco, Brazil. At the time, three forage cactus clones were used (IPA-Sertânia - IPA (Nopalea cochenillifera (L.) Salm-Dyck), Miúda - MIU (Nopalea cochenillifera (L.) Salm-Dyck) and Mexican Elephant Ear - OEM (Opuntia stricta (Haw.) Haw.)) and three sorghum cultivars (IPA-467, SF11 and Progenitor 288 - P.288 (Sorghum bicolor (L.) Moench)). The study was divided into four experiments, where experiment 1 consisted of different configurations of exclusive and consortium forage cactus-sorghum crops (OEM-EXC; IPA-EXC; MIU-EXC, SF11-EXC; P.288-EXC; 467- EXC; OEM-SF11; OEM-P.288; OEM-467; IPA-SF11; IPA-P.288; IPA-467; MIU-SF11; MIU-P.288 and MIU-467); in experiment 2 different planting density was evaluated for forage cactus (100,000; 50,000 33,333; 25,000 and 20,000 plants ha-1) under East-West cultivation guidance; experiment 3 is similar to experiment 2, differing only in the cultivation orientation, in this one it was North-South; Experiment 4 consisted of different planting densities of forage cactus and sorghum, by changing the spacing between the planting rows (50,000; 40,000; 33,333 and 28,571 plants ha-1 for the forage cactus and, 200,000; 160,000; 133,333 and 114,285 plants ha-1 for sorghum). For all experiments, the design used was in randomized blocks, with four repetitions each. From the data obtained throughout the experimental period, the productive yield of the system was determined, biological efficiency indexes, competitive ability, economic benefit, morphophysiological indexes, vegetative phenophase and ideal cutting moment. The forage cactus-sorghum consortium promoted good results in terms of forage yield, biological efficiency, competitive ability and economic benefit. The cultivation orientation did not influence the productivity of the forage cactus-sorghum consortium. On the other hand, the planting density showed positive responses with the increase in density, with better results for the higher density used. The morphophysiological indexes and the vegetative phenology of the forage cactus are influenced by the production system employed. Thus, the forage cactus-sorghum consortium is a viable alternative for semi-arid regions, with better results in the use of the OEM-467 or OEM-P.288 configuration, as well as opting for the higher planting density evaluated in the present study.