Adubação de sistemas: antecipação de adubação nitrogenada para a cultura do milho em integração lavoura-pecuária

Traditionally in no-tillage systems, fertilization is done to the catch crop. In general nutrient cycling in crop systems has not been treated as an important tool in the process of nutrient supplying for plants. The type and the condition in which vegetable residuesis decomposed can affect the efficiency of nutrient cycling.This study assessed the effect of anticipated nitrogen fertilization in crop-livestock systems on cultivated cornproduction, rate ofnutrient release from plant residue, and theN-minerallevels of soil. The study was carried out in the city Abelardo Luz (SC) in a Clayey Oxisol. The experimental design was a randomized block design with three replications. The treatments were arranged in a 2 x 2 factorial arrangement. The first factor was N Fertilization Time: in the N-Pasture level, nitrogen (200 kg ha-1 N) and N-Grains level, no nitrogen was applied. The second factor was the Grazing Height, characterized by two sward heights of oat at 15 cm (Low Height Pasture) and at 30 cm (High Height Pasture). Corn hybrid ‘Máximus’ was sowed in 10thOctober, 31 days after the removal of animals. In the twelve resulting plots from the combination of treatments on pasture phase (N Fertilization Time x Grazing Height) rates of N-fertilizer (0, 100, 200 e 300 Kg ha-1 of N) as urea were allocated in the split plot.We conclude that anticipated N fertilization of winter cover crop pasture to provide high-quality forage and carry-over N to the subsequent corn crop and may eventually replace side drees nitrogen fertilization on corn and can improve overall N fertilizer efficiency use in integrated crop-livestock systems.The rate of K release from plant residues is very fast, releasing large quantities in the first days after plant desiccation.Despite of considerably high nitrogen dose used in both the pasture and at the grain crop it was not observed nitrate leaching risks during the study period.

Sistemas de produção de milho sob adubação nitrogenada e plantas de cobertura do solo

The no-tillage system is the predominant model in the agricultural scenario of southern Brazil. Thus, the use of cover crops is significant due to the addition of biomass to protect the soil surface, and contribute to the cycling and/or fixing of nutrients, and in particular nitrogen (N) with liberation for the subsequent culture. Among the cool season species, it was found predominant use of oat to obtain straw to system. Though large quantities input of residue is not the preferred species to precede the corn, cereal with relevant importance in the Paraná Southwest region. It was aimed to evaluate the productivity capacity of corn in no-tillage, in the absence or presence of nitrogen fertilization, on waste of winter cover crops on soil and climatic conditions of the Paraná Southwest region. The installation of no-tillage was held in 2010 in the experimental area belonging to UTFPR, Campus Dois Vizinhos, on a Red Latosol. For the present study, we used data relating to three agricultural years (2012/2013, 2013/2014 and 2014/2015). The experimental design was randomized block design with split plots with three replications. The main plots consisted of systems composed by cover crops (black oat, ryegrass, rye, turnip, vetch, white lupine, aot+vetch consortium and oat+vetch+turnip), preceding corn. In the subplots were used two doses of nitrogen fertilization (0 and 180 kg ha N) coverage in maize.The biggest coverage rates occurred in the consortium with 95% at 62 days after sowing. The residual effect of 180 kg ha cool season plants following year. The residual effect of 180 kg ha systems, reduced in 21% the C/N ratio of poaceae. The common vetch accumulated 32 kg N per ton of MS added. The oat and rye keeps more than 50% waste to the land cover, after 120 days, while the ryegrass and vetch provide low soil protection. Consortium oat+vetch+turnip, vetch and white lupine, released the largest amounts of N, between 52 and 59 kg ha brassica and consortia positively influencing the diameter and length of cobs, number of kernels per row and, total number of grains per ear of corn, in the absence of mineral N. The weight of a thousand grains was increased by 12.4% by the addition of 180 kg ha increase in productivity of grain by the addition of 180 kg ha N, was 2.1 Mg ha 5.6 Mg ha 6.4 Mg ha components when cultivated on vetch. Systems containing fabaceae, brassica and consortium oat+vetch+turnip, predating the corn, in the absence of mineral N, provided similar grain yelds inrelation to the systems with the addition of 180 kg ha Keywords: Cover crops. No-tillage. Grain yield. Zea mays - 1 -1 N, increased 4.8% coverage rate in the of N in corn/cover crops -1 -1 . Fabaceae, -1 N mineral. The average N, in relation to dose 0 kg ha corn kernels on fabaceae, brassica and consortium oat+vetch+turnip, and poaceae the grains in succession. The consortium added amount between 4.0 the DM in the years of study. There was no effect of mineral N rate for corn yield components when cultivated on vetch. Systems containing fabaceae, brassica and consortium oat+vetch+turnip, predating the corn, in the absence of mineral N, provided similar grain yelds inrelation to the systems with the addition of 180 kg ha-1 N.

Altura do pasto e adubação nitrogenada sobre a produção de forragem e eficiência no uso de nutrientes em sistema de integração lavoura-pecuária

The proper use of management strategies, such as grazing intensity and nitrogen fertilization are primordial to the success of integrated crop-livestock system. Several studies have demonstrated the influence of grazing intensity and nitrogen fertilization on dynamics of forage production and nutrient cycling. However, most this researches studying these strategies in isolation and little is known about the interaction of these factors in the management of an integrated crop-livestock system. In this context, the aim of this study is to determine the best management strategy involving sward height and nitrogen fertilization, permitting greater forage production and improved efficiency in the use of nitrogen soil by a black oat ‘BRS 139’ plus ryegrass ‘Barjumbo’ pasture in integrated crop-livestock system. The experiment was realized in Abelardo Luz – SC, in an area of 14 ha, where has been conducted an experiment in long term with integrated crop-livestock system under no-tillage since 2012. The experimental design is a randomized block design with three replications in a factorial design (2x2), the first factor was the grazing intensity (high and low), characterized by two sward height management (10 and 25 cm), and the second included the time factor application of N in the system: N applied on pasture (N-pasture) and N applied on the culture of grain (N-grain), at dose of 200 kg N ha stocking and variable stocking rate. The previous crop to pasture was corn. The nitrogen fertilization of pasture increased tiller density, forage density, participation of ryegrass ‘Barjumbo’ and percentage of ryegrass leaves in forage mass. Forage mass was less at low sward height on average, however the percentage of ryegrass ‘Barjumbo’ and rye leaves was greater and dead material was lower in this treatment. With nitrogen fertilization of pasture it was possible to double the amount of forage accumulated in periods with further development of ryegrass, furthermore, the total production of DM was increased in 38.4% and the shoot N concentration in 28.6%. When the nitrogen fertilization is applied in pasture, it is possible to keep black oat ‘BRS 139’ plus ryegrass ‘Barjumbo’ pasture with an average sward height of 11 cm. The residual effect of N applied at corn was not sufficient to meet the nutritional needs of pasture and the forage production was affected by periods with N deficiency, while a single application of 200 kg N ha was sufficient to meet the N requirements throughout the forage accumulation period. The black oat ‘BRS 139’ plus ryegrass ‘Barjumbo’ pasture is efficient in use and recovery of the nitrogen applied in both treatments of sward height.

Adubação nitrogenada no milho em sucessão à plantas de cobertura sob sistemas de cultivo do solo

To achieve high yields the corn crop is dependent on nitrogen. Systems of cover crops preceding corn and form of land cultivation are essential for the best use of nitrogen by corn. This study aimed to evaluate the use or not of nitrogen fertilization in corn in succession to cover crops, planted in three cropping systems. The experimental design was randomized blocks with sub-divided portion where the main plots consisted of three cultivation systems (tillage, conventional tillage and minimum tillage), the subplots by four plant cover in monocrop (oat, hairy vetch, field peas and turnip) and sub-subplots by nitrogen fertilization (0 and 160 kg ha-1 N). Evaluations were performed, the cover crops, soil cover rate, dry matter, content and accumulation of nutrients. In corn we evaluated yield components, yield, chlorophyll and nutrient levels in leaves. Among the species coverage studied the oat showed hardiness in the experiment, covering ground faster and showing more dry matter, however vetch hairy showed higher concentrations of N, P and K and higher accumulation of N ha-1. The soil tillage system influenced the K leaf content. The interaction cultivation x coverage showed significance for the total chlorophyll of corn. In the absence of N, N content and chlorophyll were higher where the corn was sown on the pea and hairy vetch. The corn production, despite a higher average in the presence of nitrogen fertilization, did not differ significantly when used the pea and hairy vetch as a cover crop.

A altura de dossel e a adubação nitrogenada da pastagem podem afetar a nutrição nitrogenada do milho, num sistema de integração lavoura pecuária?

We conducted a field experiment near Abelardo Luz, Santa Catarina, from October 2012 to April 2014, to evaluate the effect interaction of nitrogen fertilization and height of canopy over the N nutrition of corn subsequently grown to pasture. The data belonging to this thesis are related to the first two production cycles obtained in sorghum pasture (2012/2013), oat (2013) and corn crop (2013/2014). In the evaluation of forage sorghum and oat it was used the same experimental design, consisting of randomized complete block in a factorial arrangement (2 x 2) with three replications. The first factor was considered canopy height (Low and High) and the second factor was the fertilization of cover crop pasture (0 and 200 kg N.ha-1). In phase I and II, the combination of factors evaluators were prepared in the same experimental unit. For corn crop the design was a randomized complete block in a factorial design (2X2X4X6) with three replications. Factors considered in corn were: canopy height of pasture (Low and High), nitrogen application times (NG - nitrogen in the grains and NP - nitrogen in pasture), nitrogen fertilization in corn (0, 100, 200 and 300 kg N.ha-1) and time (46, 53, 60, 67, 76 and 103 days after sowing the maize). In phases I and II, in general the use of N in the pasture increased the productive potential of the pasture and animal management and canopy height has changed the dynamics of structural components and botanical pasture. In cold conditions for long periods and not acclimatized plants the adoption of high nitrogen fertilization and height high grazing pasture leave vulnerable to damage caused by the freezing of plants. The anticipation of nitrogen fertilization on pasture positively affects the corn crop by increasing the accumulated dry matter and N content in the plant. Nitrogen nutritional content of corn with the anticipation of fertilization in pasture is suitable for obtaining high crop production in integrated crop-livestock system. When used nitrogen only coverage in corn sufficiency level in the nitrogen nutrition is achieved with the use of 100 kg N.ha-1. With the use of 200 kg N ha -1 NG and NP no difference in nitrogen content and nitrogen nutrition index.