Determination of a long-term optimal irrigation strategy for dry beans in Parana State, Brazil

Abstract

The economical benefits of different irrigation strategies were assessed by long term simulation (20 years) for dry beans in Paraná, Brazil. The model BEANGRO was used to simulate crop yield and irrigation requirements assuming eight levels of irrigation threshold (20 to 90% of the remaining soil available water in steps of 10%), in addition to a level considering no irrigation. Net return was the objective function to select the optimum irrigation management strategy, assuming fixed and stochastic distributions of historical product price. The results showed that yield was significantly increased by irrigation despite a high variability for all the simulation strategies, due to variations on growth conditions over the years. Although the net return was highly variable, it was positive in 75% of the years for all strategies with threshold values higher than 30%. The strategy of irrigating the crop before the soil reaches 60% AW provided the maximum economical benefits. The high profit using this improved strategy justifies the practice of irrigation for beans in Paraná.

The performance of the CROPGRO model for bean (Phaseolus vulgaris L.) yield simulation

“…In addition, the RMSE was low (2.47%). These results are consistent with previous studies that showed that the model appeared to simulate the phenology of the bean cultivars adequately (FARIA et al, 1997;MEIRELES et al, 2002). …”

“…In Brazil, Faria et al (1997) used simulations with CROPGRO-Dry bean to evaluate different strategies for the irrigation management of beans in the State of Paraná. Meireles et al (2003) calibrated the CROPGRO-Dry bean model to quantify decreases in the yield of beans sown on 36 sowing dates in Santo Antônio de Goiás, Goiás State.…”

Risco climático de quebra de produtividade da cultura do feijoeiro em Santo Antônio de Goiás, GO

“…A transpiração é proporcional à energia interceptada pelo dossel da cultura e a evaporação do solo depende da quantidade de energia que atinge a superfície do solo, sendo afetadas por índice de área foliar, albedo do solo, e teor de água no solo (FARIA et al, 1997a).…”

“…Dentre os estudos já realizados utilizando-se o CROPGRO-Dry Bean, destacam-se: avaliação de diferentes estratégias de manejo de irrigação visando ao melhor benefício econômico para a cultura do feijoeiro no Estado do Paraná (FARIA et al, 1997a); calibração do modelo BEANGRO para o feijoeiro nas condições de Londrina, PR, com intuito de testar sua performance em simular a fenologia, produção de matéria seca e grãos desta cultura sob diferentes condições ambientais (FARIA et al, 1997b); determinação das épo-cas de semeadura com menores riscos para a cultura do feijoeiro, em condições de sequeiro e irrigada, em Santo Antônio de Goiás (GO), utilizando as produtividades potencial e real, e a quebra relativa de produtividade simulada pelo CROPGRO-Dry Bean (MEIRELES, 2000e MEIRELES et al, 2001; determinação da necessidade de irrigação pela cultura do feijoeiro no nordeste da Bacia do Rio Tibagi, no Estado do Paraná, utilizando-se o CROPGRO-Dry Bean associado a um sistema de informações geográficas para regionalizar as informações (HEINEMANN e HOOGENBOOM, 2001). …”

Calibration and test of the cropgro-dry bean model for edaphoclimatic conditions in the savanas of Central Brazil

“…For the dry bean, for instance, Faria et al (1997b) calibrated the BEANGRO model for the conditions of Londrina, PR -Brazil, testing its performance under several environmental conditions. Although some modifications were necessary, results indicated that the model is adequate to estimate phenology and grain yield for two cultivars for several sowing dates and moisture regimes, allowing its use for climatic risk and technical and economical viability studies of this crop under arid and irrigated conditions.…”