ABSTRACT It was evaluated how straw management modifies the development, growth, nutrient cycling and crop water productivity of sugarcane in the semiarid region of Brazil. The experiment was carried out using two plots with 5 ha each, being one without straw on the soil surface and one with 26 Mg·ha-1 covering the soil. Sugarcane growth and development and straw decomposition coefficient were evaluated, whereas the industrial yield, juice quality, dry matter partitioning, and crop water productivity were determined at harvesting. The straw decomposition coefficient was 0.0049 Mg·ha-1·day-1, and the remaining dry mass was equal to 24%. The straw affected the sugarcane growth and development until the first 100 days. The individual internode volume can be adopted as an indicator of the effect of straw on sugarcane growth because the internode volumes up to the sixth position in the with-straw treatment crop were lower than in the no-straw treatment, which was not observed in other variables of the stalks. Keeping straw on the soil surface reduced the crop lodging. Yield and juice quality were not affected, but crop water productivity was increased by keeping sugarcane straw in the field.

ABSTRACT It was evaluated how straw management modifies the development, growth, nutrient cycling and crop water productivity of sugarcane in the semiarid region of Brazil. The experiment was carried out using two plots with 5 ha each, being one without straw on the soil surface and one with 26 Mg·ha-1 covering the soil. Sugarcane growth and development and straw decomposition coefficient were evaluated, whereas the industrial yield, juice quality, dry matter partitioning, and crop water productivity were determined at harvesting. The straw decomposition coefficient was 0.0049 Mg·ha-1·day-1, and the remaining dry mass was equal to 24%. The straw affected the sugarcane growth and development until the first 100 days. The individual internode volume can be adopted as an indicator of the effect of straw on sugarcane growth because the internode volumes up to the sixth position in the with-straw treatment crop were lower than in the no-straw treatment, which was not observed in other variables of the stalks. Keeping straw on the soil surface reduced the crop lodging. Yield and juice quality were not affected, but crop water productivity was increased by keeping sugarcane straw in the field.

ABSTRACT. Agricultural production in semi-arid regions is limited due to water availability. In addition, the water quality available for irrigation is often compromised due to the high salt content present. Millet is a forage species considered tolerant to water deficit and moderately salt tolerant. In view of the above, the objective was to evaluate the growth of millet under water and saline stress associates. The experiment was carried out in a randomized block design, in a 4x3 factorial scheme, composed of four levels of water replacement, based on crop evapotranspiration (ETc): 25%.ETc, 50%.ETc, 75%.ETc and 100%.ETc and three levels of water salinity (0.03, 2.0 and 4.0 dS m-1). With 25%.ETc independent of salinity, all morphological characteristics of millet were affected, occurring death of plants in the initial growth phase. In the absence of salt and greater availability of water, greater plant growth occurred. With respect to salinity, there was a reduction in the increment of all variables evaluated, with the highest reduction at the highest saline level (4.0 dS m-1). Water and salt stresses, when associated, reduce the growth of millet, since concentrations above 2.0 dS m-1 and less than 50%.ETc compromise its full development, providing declines in yield.

ABSTRACT. Agricultural production in semi-arid regions is limited due to water availability. In addition, the water quality available for irrigation is often compromised due to the high salt content present. Millet is a forage species considered tolerant to water deficit and moderately salt tolerant. In view of the above, the objective was to evaluate the growth of millet under water and saline stress associates. The experiment was carried out in a randomized block design, in a 4x3 factorial scheme, composed of four levels of water replacement, based on crop evapotranspiration (ETc): 25%.ETc, 50%.ETc, 75%.ETc and 100%.ETc and three levels of water salinity (0.03, 2.0 and 4.0 dS m-1). With 25%.ETc independent of salinity, all morphological characteristics of millet were affected, occurring death of plants in the initial growth phase. In the absence of salt and greater availability of water, greater plant growth occurred. With respect to salinity, there was a reduction in the increment of all variables evaluated, with the highest reduction at the highest saline level (4.0 dS m-1). Water and salt stresses, when associated, reduce the growth of millet, since concentrations above 2.0 dS m-1 and less than 50%.ETc compromise its full development, providing declines in yield.