ABSTRACT This study aimed to evaluate the effect of water supply and sowing time on yield and yield components of two corn hybrids grown during offseason in the region of Dourados-MS, Brazil. The experimental design was randomized blocks in sub-divided plots, with four replications. In the main plot, two sowing dates were defined (2013 crop year: February 27 and March 27; and 2014 crop year: March 18 and April 5). In subplots, irrigation management systems were defined (irrigated and rainfed). Hybrids AS 1555 and AS 1590 were grown in the sub-plots. The parameters evaluated were plant height, ear insertion height, stem diameter, ear length and diameter, 100-grain weight, and grain yield. Regardless of irrigation and hybrid used, sowing time significantly affected corn yield, which responded to climate changes throughout crop cycle. Water supply increased corn yield, with the highest value being of 9338 kg ha-1 (156 bags ha-1) and obtained when irrigated AS 1555 hybrid was sown on February 27, 2013.

ABSTRACT Sugarcane requires planning aimed at maintaining production levels, technological quality, and longevity of the sugarcane field, as it is a semi-perennial crop. To this end, the adoption of soil management systems associated with the maintenance of remaining straw are some of the strategies aimed at protecting the soil structure and its properties vital to the sustainability of agricultural systems. In this context, this study aimed to evaluate the influence of soil management systems and remaining straw with and without ratoon chiseling on the optimum water range (OWR) and load-bearing capacity (LBC) of the soil. The experimental design consisted of randomized blocks in a split-plot scheme, with four replications. The plots were composed of no-tillage and conventional tillage, the subplots consisted of three levels of remaining straw (0, 50, and 100%), and the sub-subplots consisted of the use or not of chiseling. Samples with preserved structures were collected at depths of 0.05 and 0.15 m for the analysis of the physical indicators OWR and LBC. Maintaining 100% straw associated with the use of chiseling resulted in an increase in OWR in both soil management systems and depths. Maintaining straw at 50 and 100% also led to lower LBC values in the evaluated soil management systems and depths, suggesting an improvement in soil physical quality. The use of chiseling of ratoons in conventional tillage promoted higher LBC values, indicating possible additional soil compaction in these areas.

ABSTRACT The area cultivated with sugarcane in Mato Grosso do Sul, Brazil, has increased significantly in recent years, in which to meet the demand of the mills, the use of adapted varieties has proved to be a fundamental strategy, combined with the use of irrigation, especially in periods of water deficit. The study aimed to evaluate the growth and yield of four sugarcane varieties (CTC 4, RB966928, RB975201, and RB92579) in plant cane cultivated with and without irrigation. The experiment was conducted at Embrapa Western Agriculture (Embrapa Agropecuária Oeste) in Dourados, MS, Brazil. A randomized block design arranged in a 2 x 4 factorial scheme with three replications was used. At 90, 150, 210, 270, 330, and 390 days after planting (DAP), stalk height and diameter, leaf area index (LAI), and dry biomass were evaluated. The soil cover percentage (%SC) was determined through aerial images taken with a drone, with evaluations made from planting to the maximum soil cover. Total recoverable sugar (TRS), number of stalks m-1, stalk (STY), and sugar (SGY) yield were evaluated at 390 DAP (harvest). The RB975201 variety has the highest growth in height, stem diameter, and LAI when grown under irrigation or without irrigation, and the CTC 4 variety has the smallest. The irrigated production system increases the growth of stalks, LAI, and degree of soil cover for the sugarcane varieties in plant cane and a greater amount of stems m-1, STY, and SGY, highlighting the varieties RB92579 and RB975201.

RESUMO A área cultivada com cana-de-açúcar em Mato Grosso do Sul, Brasil tem aumentado significativamente nos últimos anos, em que para atender à demanda das usinas o uso de variedades adaptadas tem se mostrado estratégia fundamental, aliado ao uso da irrigação, sobretudo em períodos de déficit hídrico. Objetivou-se avaliar o crescimento e a produção de quatro variedades de cana-deaçúcar (CTC 4, RB966928, RB975201, RB92579), em cana-planta, cultivadas sob irrigação e sequeiro. O experimento foi conduzido na Embrapa Agropecuária Oeste, em Dourados, MS, Brasil em um delineamento em blocos ao acaso, em esquema fatorial 2 x 4, com três repetições. Aos 90, 150, 210, 270, 330 e 390 dias após o plantio (DAP) avaliou-se a altura e o diâmetro de colmos, o índice de área foliar (LAI) e a biomassa seca. O percentual de cobertura do solo (% SC) foi determinado, através de imagens aéreas tomadas com drone, com avaliações feitas desde o plantio até a máxima cobertura do solo. O açúcar total recuperável (TRS), o número de colmos m-1, a produtividade de colmos (TSH) e de açúcar (TUH) foram avaliados aos 390 DAP (colheita). A variedade RB975201 apresenta maior crescimento em altura, diâmetro de colmo e LAI quando cultivada em sequeiro ou irrigação, a variedade CTC4, o menor. O sistema produtivo irrigado proporciona aumento no crescimento de colmos, LAI e grau de cobertura do solo para as variedades de cana-deaçúcar, em cana-planta, assim como maior quantidade de colmos m-1, TSH e TUH, destacando-se as variedades RB92579 e RB975201.

Objetivou-se avaliar o desempenho de quatro sistemas para compostagem de carcaça de aves pelo monitoramento diário da temperatura, análise da presença ou ausência de Salmonella sp., contagem de coliformes totais (CT) e fecais (CF) e reciclagem de nutrientes. Os sistemas avaliados foram: Leira com aeração (LCA), Leira sem aeração (LSA), Composteira com aeração (CCA) e Composteira sem aeração (CSA). O processo de compostagem foi conduzido em dois estágios. No primeiro, as carcaças foram intercaladas com cama de aviário, palha e água. No segundo estágio, a massa de compostagem foi transferida para um pátio onde o material foi revolvido e umedecido semanalmente até a estabilização. Detectou-se a presença de Salmonella sp nos sistemas LSA e CSA ao final do primeiro estágio, desaparecendo após o segundo estágio. No composto, observou-se redução do número de CT e CF e dos teores de N e C, além de acréscimo dos demais nutrientes. Concluiu-se a favor da realização da compostagem em qualquer um dos sistemas avaliados e importante realizar um segundo estágio da compostagem, tanto para eliminação de patógenos como para obtenção de um composto com melhores características agronômicas.

The aim of present study was to evaluate the performance of four poultry carcasses composting systems through daily temperature monitoring, in the absence and presence of Salmonella sp., total (TC) and faecal coliforms (FC) number and nutrients recycling. The evaluated systems were: Piles with aeration (1), Piles without aeration (2), Composters with aeration (3) and Composters without aeration (4). The process was carried out in two stages. The first stage was performed by arranging the carcasses with straw and water. In the second stage the compostage mass was transferred to a composting area where the material was revolved and wetted weekly until stabilization. The presence of Salmonella sp in the systems 2 and 4 at the end of the first stage was detected disappearing after the second one. In the compost a reduction in the number of TC and FC and of N and C contents as well as an increase in the rest of nutrients by the end of second stage was observed. It may be concluded that it is possible to perform the poultry carcass composting in anyone of the evaluated systems and is important to perform a second stage in the composting process to eliminate pathogens as well as to obtain a compost with better agronomic characteristics.