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The objective of this work was to determine the effect of desiccation and haymaking periods in the off-season on the quality of hay produced and nutrient accumulation, as well as to quantify the effects of remaining dry mass on the establishment and development of soybean in lowland areas. The experiment was conducted in the field in the 2015/16 and 2016/17 growing season in the lowland area of the Federal University of Santa Maria, Rio Grande do Sul, Brazil. Two treatments of ryegrass management (hay and desiccation) in five periods and one fallow period were tested. The study implemented an experimental randomized block design. The following variables were measured in the off-season: ryegrass dry shoot mass, hay quality parameters, moisture and nutrient content in the soil. In addition, the initial population of plants, dry shoot mass, nodule dry mass and grain yield were determined in the soybean. The cultivation of ryegrass hay in lowland area is a viable alternative. However, it reduces the potassium content in the soil if it is not replaced by fertilization. The use of ryegrass, regardless of the period of haymaking or desiccation, increases the water retention in the soil, which promotes straw wrapping and/or mirroring of the soil in a year of elevated precipitation, with a consequent reduction of the initial plant population and soybean grain yield when compared to the fallow system. [ABSTRACT FROM AUTHOR]

The barley culture has been conquering space in Southern Brazil, being an option for rotation with wheat. One of the main constraints for the increased productivity is the race against weed, especially ryegrass. Therefore, this study aimed to evaluate the barley competitive ability (Hordeum vulgare) against the ryegrass (Lolium multiflorum), in relation to the nitrogen absorption and to measure the density in which the culture is negatively affected. For this, a field experiment was conducted using experimental designs of randomized blocks, where the barley coexisted with different ryegrass densities (0, 4, 16, 32, 64 and 128 m-2). The analyzed varieties were plant height, chlorophyll, number of barley and ryegrass stems, barley and ryegrass dry mass, leaf area, number of spikes, number of grains per spike, the weight of a thousand grains and yield. The ryegrass interferes negatively on the barley's development and productivity, even in low densities, being necessary its control to four plants m-2. [ABSTRACT FROM AUTHOR]