Níquel em solo e plantas de milho cultivadas em área tratada com lodo de esgoto durante 15 anos consecutivos

Pós-graduação em Agronomia (Ciência do Solo) - FCAV

Quantitative descriptors and their direct and indirect effects on corn yield

The objective of this study was to evaluate the direct and indirect effects of ten quantitative descriptors of agronomic importance in productivity of 25 maize hybrids and their respective influences of heritability. The experiment in randomized blocks with four replications, was conducted in 2010/2011 crop in a soil under humid subtropical climate. The quantitative descriptors were: ear length, ear diameter, cob diameter, number of rows of grains, stem diameter, plant height, ear height, weight of 100 grains, grain weight per ear and number of grains per ear. The grain weight per ear and ear length showed high correlation with grain yield, and the descriptors with the highest potential for selecting superior genotypes and showing high heritability.

Leaf application of silicic acid to upland rice and corn

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Nutritional value of high moisture corn silage in the diet of Holstein cows

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Nitrogen fertilization (15NH4NO3) of palisadegrass and residual effect on subsequent no-tillage corn

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

RESPONSE OF CORN GROWN IN TILLAGE SYSTEM FOR THE APPLICATION OF NITROGEN DOSES IN A SEQUENCE OF PLANT COVER

The use of cover crops can produce large amounts of biomass, improving the cycling of nutrients, particularly nitrogen, promoting productivity gains and cost savings. Given this, the objective was to evaluate the use of N rates associated to cover crops grown in pre-harvest nutritional status, nitrogen accumulation and corn yield in both years. The experiment was conducted in an Oxisol with maize, no-tillage system. The experimental design was a randomized block, split plot with four replications. The main treatments were: six cropping systems (sun hemp, jack bean, lablab, millet, and velvet bean fallow) in secondary treatments: four doses of nitrogen (0, 60, 120 and 180 kg ha(-1) N). Corn yield was not affected by the type of coverage for pre-season, regardless of the nitrogen applied in the soil. Still, the use of nitrogen fertilizer in the soil promotes gains in grain yield in the first year of cultivation, regardless of the type of coverage in pre-season. In the first year (2006/2007) the species of coverage produced more biomass were velvet bean, jack bean, sun hemp and lablab, while in the second year (2007/08) were the sun hemp, millet, lablab, jack bean and velvet bean, respectively.

Apparent protein and energy digestibility and amino acid availability of corn and co-products in extruded diets for nile tilapia, oreochromis niloticus

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Agronomic and chemical characteristics of hybrid corn to ensiling

Our aim was to evaluate agronomic and chemical characteristics of corn hybrids to ensiling. It were evaluated nine corn hybrids (MX 300, RB 9308, 2B655, XB 6012, GNZ 2500, PL6890, PRE 32D10, PRE 22T10 e AG 1051), with three replicates. The higher fresh matter yield were observed in the hybrids PL6890 and PRE 32D10, while the dry matter yield was observed in the hybrid PRE 32D10 (13.43 t ha(-1)). The hybrids PRE 32D10 and PRE 22T10 stood out to present higher percent of leaf in relation to whole plant, while the lower percent of stems was found in the hybrids MX 300, 2B655 and XB 6012, however the higher leaves: stems relation was found in XB 6012 (0.49). There was higher CP content in the hybrid PRE 32D10 (9.10% of DM), while the lower NDF (57.78% of DM) and cellulose content (24.27% of DM) were observed in the hybrid GNZ 2500. The hybrid PL6890 presented higher ADF and lignin contents, the others hybrids had values lower. The lower NDIN content was observed in the hybrid RB 9308, while the lower AIDN content occurred on the hybrid 2B655. The lower buffer capacity was observed in the hybrid 2B655 (0.29). There are some differences on chemical composition among the corn hybrids used in this study, however, it is recommended to use the hybrids MX 300, PL6890 and PRE 32D10 for showing higher dry matter yield, which may reflect in the amortization of silage production costs.

Site and extent of amino acid digestion in dairy cattle fed with corn and its byproducts

The study was conducted to evaluated the site and extent of dry matter (DM), crude protein (CP), methionine (Met), lysine (Lys), and threonine (Thr) digestion of corn and byproducts obtained from corn germ mixed with different amounts of extruded or non-extruded ether extract (EE) in dairy cattle. Treatments consisted in eight types of feed and two processing in a 4 x 2 factorial design. There were four feeds: corn grain cracked (Corn), corn germ meal with 1% EE (CG1), corn germ meal with 7% EE (CG7), and corn germ meal with 10% EE (CG10). The feeds were processed in one of two ways: extruded (Ex) and not extruded. In situ techniques were used to determine DM, CP, Met, Lys, and Thr partial and total tract digestion. A basic diet was compounded of corn germ meal, soybean meal and coastcross hay in a 70: 30 roughage to concentrate ratio. There was no interaction (P>0.05) between feeds and processing method. Extrusion improved (P<0.05) total tract digestibility of corn DM but not CP. Intestinal digestibility was similar (P>0.05) for corn and corn germ meal mixed with 7 and 10% EE, regardless of EE processing method. The CP total tract digestibility of corn germ meal with 1% non-extruded EE was 16.62% higher (P<0.05) than that of the extruded form. The best total CP digestibility was obtained for corn germ meal with 7% EE, independently of the processing method. The effects of EE processing method on partial and total digestibility differed between amino acid. Corn and corn byproduct extrusion may improve dry matter digestibility, but do not necessarily influence crude protein digestion. Ruminal and intestinal digestibility of Met, Lys, and Thr depends on both feed type and processing method. Therefore, amino acid availability should be considered individually.

Desempenho técnico e econômico de forrageiras tropicais em sistema integrado de produção no cerrado de baixa altitude

Pós-graduação em Agronomia - FEIS

Degradabilidade do amido de grãos secos e ensilados de híbridos de milho com textura dura e dentada em função do grau de moagem

This research evaluated corn grains with flint and dent texture (ensiled high-moisture or dried), submitted to grinding degrees, using the in situ ruminal degradation technique. Three rumen canulated adult sheeps were used in a complete randomized design, using a factorial outline 2 x 2 x 3, with two corn hybrids (flint and dent texture), two conservation methods (ensiled high-moisture and dry) and three grinding degress (whole, coarsely and finely ground, corresponding to the sieve of 12; 10 and 8 mm). Starch soluble fraction (A) of the dent hybrid ensiled corn grains was greater comparing to the dry materials and in both conservation forms this fraction was reduced in the flint texture hybrid, while the insoluble fraction potentially degradable (B) the opposite occurred. The degradation potential was higher in grains ensiled in two textures. The ensiled allowed more starch effective degradation in relation to dry grain in two textures and the grains dent texture hybrid also increased such degradation in both conservation methods. The dent texture and the ensiled high-moisture grains proved the best option considering the starch degradability. Regardless of the conservation forms, the grains of corn hybrid flint texture should be finely ground, for providing higher ruminal degradation, while for the dent texture hybrid, the coarsely and whole grinding are the most suitable for ensiled and dry grain, respectively.

Degradabilidade da matéria seca e da proteína bruta de grãos secos e de silagens de grãos úmidos de híbridos de milho (Zea mays), submetidos a diferentes processamentos

The objective of this work was to evaluate the effect of processing two corn hybrids conserved, dry and humid grains, the dry matter (DM) and crude protein (CP) degradability in situ. The particle size was determined and difference was verified in MGD (Medium Geometric Diameter) of processed ingredients. Three sheep were used with rumen canulated, in a completely randomized design, using a factorial outline 2 x 2 x 3, being two corn hybrid, two conservation methods and three processing forms (whole, coarsely and finely ground), with five times of incubation (3, 6, 12, 24 and 48 hours). The fraction A in SDC (silage of dent corn) of DM was superior to GDC (grain of dent corn) in all of the particles size. The ensiling process increased the DM solubility, reducing the fraction B in comparison to dry grain. The values regarding the fractions DP and DE the 5% per hour of the protein, were larger for SDC and GDC, it presents a decreasing when the incubation time advances. The fermentation rate was superior for SDC and GDC. The ensiling process has positive effect in the decreasing of DM and CP in comparison to GDC.

Yield potential and resource-use efficiency of maize systems in the western U.S. Corn Belt

Maize demand for food, livestock feed, and biofuel is expected to increase substantially. The Western U.S. Corn Belt accounts for 23% of U.S. maize production, and irrigated maize accounts for 43 and 58% of maize land area and total production, respectively, in this region. The most sensitive parameters (yield potential [YP], water-limited yield potential [YP-W], yield gap between actual yield and YP, and resource-use efficiency) governing performance of maize systems in the region are lacking. A simulation model was used to quantify YP under irrigated and rainfed conditions based on weather data, soil properties, and crop management at 18 locations. In a separate study, 5-year soil water data measured in central Nebraska were used to analyze soil water recharge during the non-growing season because soil water content at sowing is a critical component of water supply available for summer crops. On-farm data, including yield, irrigation, and nitrogen (N) rate for 777 field-years, was used to quantify size of yield gaps and evaluate resource-use efficiency. Simulated average YP and YP-W were 14.4 and 8.3 Mg ha-1, respectively. Geospatial variation of YP was associated with solar radiation and temperature during post-anthesis phase while variation in water-limited yield was linked to the longitudinal variation in seasonal rainfall and evaporative demand. Analysis of soil water recharge indicates that 80% of variation in soil water content at sowing can be explained by precipitation during non-growing season and residual soil water at end of previous growing season. A linear relationship between YP-W and water supply (slope: 19.3 kg ha-1 mm-1; x-intercept: 100 mm) can be used as a benchmark to diagnose and improve farmer’s water productivity (WP; kg grain per unit of water supply). Evaluation of data from farmer’s fields provides proof-of-concept and helps identify management constraints to high levels of productivity and resource-use efficiency. On average, actual yields of irrigated maize systems were 11% below YP. WP and N-fertilizer use efficiency (NUE) were high despite application of large amounts of irrigation water and N fertilizer (14 kg grain mm-1 water supply and 71 kg grain kg-1 N fertilizer). While there is limited scope for substantial increases in actual average yields, WP and NUE can be further increased by: (1) switching surface to pivot systems, (2) using conservation instead of conventional tillage systems in soybean-maize rotations, (3) implementation of irrigation schedules based on crop water requirements, and (4) better N fertilizer management.

RP92-217 No. 19 Cost of Grain Storage

Grain marketing decisions are among the toughest the farm owner/operator or manager must make. Grain producers store grain to speculate on receiving higher prices, earn a return above storage costs, or to take advantage of government programs. Prices must increase enough to cover the additional costs, or forward contract prices must exceed current prices by more than the cost of storage in order to justify forward pricing. The gain in prices received can come from both changes in price level and changes in basis. This research publication discusses all the areas of the cost of grain storage.

Phosphorus utilization by corn as affected by green manure, nitrogen and phosphorus fertilizers

The objective of this work was to evaluate the utilization by corn plants of P from triple superphosphate fertilizer labeled with P-32 (P-32-TSP), and of P from soil as affected by N rates and by the green manures (GM) sunn hemp (Crotalaria juncea) and millet (Pennisetum glaucum). The experiment was carried out using pots filled with 5 kg Oxisol (Rhodic Hapludox). A completely randomized design was used, in a 4x4x2 factorial arrangement, with four replicates. The treatments were: four P rates as TSP (0, 0.175, 0.350, and 0.700 g P per pot); four N rates as urea (0, 0.75, 1.50, and 2.25 g N per pot); and sunn hemp or millet as green manure. The additions of N and P by the GM were taken into account. After grain physiologic maturation, corn dry matter, P contents, accumulated P, and P recovery in the different treatments were measured. P-32-TSP recovery by corn increased with N increasing rates, and decreased with increasing rates of P-32-TSP. The mineral fertilizer provides most of the accumulated P by corn plants. The recovery of P-32-TSP by corn was 13.12% in average. The green manure species influence the assimilation of P-32-TSP by the plants.