Jucenei Fernando Frandoloso

Atributos químicos de solo e resposta do trigo e da soja ao gesso em sistema semeadura direta

A aplicacao de gesso para tornar o Al indisponivel, assim como para suprir nutrientes do solo para as plantas, pode proporcionar condicoes para a obtencao de elevada produtividade das culturas. Este trabalho teve como objetivo avaliar o efeito do gesso (0, 1.000, 2.000, 3.000, 4.000 e 5.000 kg ha-1) nas caracteristicas quimicas de duas areas com Latossolo Vermelho eutroferrico de textura argilosa, com ou sem Al trocavel, e na nutricao mineral e produtividade das culturas de trigo e soja em sistema semeadura direta. As doses de gesso foram aplicadas em superficie seis meses apos a calagem. Aos seis e 12 meses apos a aplicacao do gesso, foram coletadas amostras de solo nas profundidades de 0-0,10; 0,10-0,20 e 0,20-0,40 m. O uso de ate 5.000 kg ha-1 de gesso resultou em aumento dos teores de Ca2+ e SO42- e lixiviacao de K+ ate 0,20 m e Mg2+ ate 0,40 m de profundidade, um ano apos a aplicacao, sendo a dose de 3.000 kg ha-1 a que proporcionou maior reducao do Al trocavel. A aplicacao de gesso implicou aumento dos teores foliares de Ca e Mg na cultura da soja, reducao dos teores de Ca e Mg na cultura do trigo e aumento no teor de S em ambas as culturas, enquanto o teor de K aumentou ate a dose de 3.170 kg ha-1 de gesso na cultura da soja. A utilizacao do gesso eleva a produtividade do trigo, cultivar CD 104, em solo com presenca de Al trocavel, mas nao influencia a produtividade da soja em ambas os solos, com ou sem Al.

Espaçamento e adubação nitrogenada e potássica em cobertura na cultura do milho

This work had the objective of evaluate the effect of row spacing reduction and nitrogen and potassium fertilization in covering, in the efficiency of absorption of nutrients, in the grain yield and components of the production and other agronomic traits of maize single-cross hybrid. The experiment was installed in Cascavel, State of Parana, in the agricultural year of 2004/05. It was studied three row spacings (0.45; 0.67 and 0.90m), with a population of 55000 plants ha -1 . The experiment design used was that of randomized blocks with four repetitions, in a split plot scheme. It was used 13 combinations of seven nitrogen doses (8; 20; 40; 80; 120; 140 e 152 kg ha -1 of N) with seven potassium doses (3; 7.5; 15; 30; 45; 52.5 e 57 kg ha -1 of K 2 O), adding 39 treatments. The reduction of interlineations spacing of 0.90 m to 0.45 m maintaining the same population in each area caused the increase of whole dry biomass production, more efficiency in the nitrogen and potassium absorption and also more efficiency in using N and K in the grain. The grain productivity was statistically the same in the three spacings studied. It was verified a linear increase in the productivity and of the dry biomass production in the aerial part until the doses of 152 kg ha -1 of N in covering. The fertilization with potassium proportioned an increase of dry biomass production in the aerial part, but does not influenced in the productivity. Over 80 kg ha -1 doses of N and 30 kg ha -1 of K 2 O resulted in a smaller efficiency in using nitrogen and potassium fertilization.

Eficiência de adubos fosfatados associados ao enxofre elementar na cultura do milho

The agronomic efficiency of phosphate fertilizers may be affected by phosphorus sources, soil properties, application methods and plant species. The objective of this work was to compare the efficiency of natural reactive phosphate (NRP) and triple super-phosphate (TSP) associated with elemental sulfur applied in the planting furrow of corn. The experiment was conducted in an Oxisol, in the city of Toledo-PR. The treatments were arranged in a randomized block design, in a factorial scheme 2x4x2, with two P sources (TSP and FNR), three fertilizer doses (100, 200 and 300 kg ha-1 P2O5), a control for each source, with or without addition of elemental sulfur (0 and 30 kg ha-1 S) applied at planting, with four replications. The plots consisted of four rows (6 m in length) spaced 0,90 meters. The plot usable area was formed by the center two rows, with 50 cm on each end of the plot left as border. N and K fertilization and the treatments with P and S were done by hand in the furrow and the hybrid Agroceres 8021 was sown subsequently. TSP provided the highest yields compared with NRP in the first year of cultivation. The agronomic efficiency of the NRP was 43 % and 33 % with and without S, respectively. The phosphorus content in leaf tissue was lower with NRP. The elemental S at 30 kg ha-1 did not interfere on the soil pH, but the efficiency of the phosphate fertilization was higher with the sulfur application.

Row spacing and nitrogen and potassium fertilization in covering for the corn culture.

This work had the objective of evaluate the effect of row spacing reduction and nitrogen and potassium fertilization in covering, in the efficiency of absorption of nutrients, in the grain yield and components of the production and other agronomic traits of maize single-cross hybrid. The experiment was installed in Cascavel, State of Parana, in the agricultural year of 2004/05. It was studied three row spacings (0.45; 0.67 and 0.90m), with a population of 55000 plants ha -1 . The experiment design used was that of randomized blocks with four repetitions, in a split plot scheme. It was used 13 combinations of seven nitrogen doses (8; 20; 40; 80; 120; 140 e 152 kg ha -1 of N) with seven potassium doses (3; 7.5; 15; 30; 45; 52.5 e 57 kg ha -1 of K 2 O), adding 39 treatments. The reduction of interlineations spacing of 0.90 m to 0.45 m maintaining the same population in each area caused the increase of whole dry biomass production, more efficiency in the nitrogen and potassium absorption and also more efficiency in using N and K in the grain. The grain productivity was statistically the same in the three spacings studied. It was verified a linear increase in the productivity and of the dry biomass production in the aerial part until the doses of 152 kg ha -1 of N in covering. The fertilization with potassium proportioned an increase of dry biomass production in the aerial part, but does not influenced in the productivity. Over 80 kg ha -1 doses of N and 30 kg ha -1 of K 2 O resulted in a smaller efficiency in using nitrogen and potassium fertilization.

Influência da densidade do solo no desenvolvimento inicial do pinhão-manso cultivado em Latossolo Vermelho eutroférrico

Influence of soil density on the early growth of Jatrophacurcas L. cultivated in Oxisol The objective of this work was to evaluate theinfluence of soil densities on the early growth ofthephysic nut(JatrophacurcasL.). The experiment wascarried out in 10.6 dm 3 pots in a greenhouse.The soilused in the experiment wasa clay-texture Oxisolcollected in Marechal Cândido Rondon, Parana State, Brazil. The experimental designwas randomized blockswith five levels ofsoil density (1.08, 1.22, 1.36, 1.50and 1.64kg dm -3 ) with four repetitions. Biometric and plant tissue evaluations were performed 120 days after plant emergence.It was found a reduction by 25% in plant heightat a density of1.64kg dm -3 when compared todensity of1.08kg dm -3 . For root length, the reduction was approximately 24%, 35%, 54% and 66%at the densities of1.22,1.36,1.50 and1.64 kg dm -3 ,