Annual crop rotation of tropical pastures with no-till soil as affectedby lime surface application.

Soil acidity and low natural fertility are the main limiting factors for grain production in tropical regionssuch as the Brazilian Cerrado. The application of lime to the surface of no-till soil can improve plant nutrition, dry matter production, crop yields and revenue. The present study, conducted at the Lageado Experimental Farm in Botucatu, State of São Paulo, Brazil, is part of an ongoing research project initi-ated in 2002 to evaluate the long-term effects of the surface application of lime on the soil?s chemical attributes, nutrition and kernel/grain yield of peanut (Arachis hypogaea), white oat (Avena sativa L.) and maize (Zea mays L.) inter cropped with palisade grass (Urochloa brizantha cv. Marandu), as well as the forage dry matter yield of palisade grass in winter/spring, its crude protein concentration, estimated meat production, and revenue in a tropical region with a dry winter during four growing seasons. The experiment was designed in randomized blocks with four replications. The treatments consisted of four rates of lime application (0, 1000, 2000 and 4000 kg ha−1), performed in November 2004. The surface application of limestone to the studied tropical no-till soil was efficient in reducing soil acidity from the surface down to a depth of 0.60 m and resulted in greater availability of P and K at the soil surface. Ca and Mg availability in the soil also increased with the lime application rate, up to a depth of 0.60 m. Nutrient absorption was enhanced with liming, especially regarding the nutrient uptake of K, Ca and Mg by plants.Significant increases in the yield components and kernel/grain yields of peanut, white oat and maize were obtained through the surface application of limestone. The lime rates estimated to achieve the maximum grain yield, especially in white oat and maize, were very close to the rates necessary to increase the base saturation of a soil sample collected at a depth of 0?0.20 m to 70%, indicating that the surface liming of 2000 kg ha−1is effective for the studied tropical no-till soil. This lime rate also increases the forage dry matter yield, crude protein concentration and estimated meat production during winter/spring in the maize-palisade grass inter cropping, provides the highest total and mean net profit during the four growing seasons, and can improve the long-term sustainability of tropical agriculture in the Brazilian Cerrado.

Development of tahiti acid lime [Citrus latifolia (YU. Tanaka) Tanaka] budded trees in combination with different rootstocks.

2016

Growth, mineral composition, fruit yield, and mycorrhizal colonization of feijoa in response to lime and phosphorus application.

2016

Different doses of phosphorous and lime on Paspalum regnellii crop.

2016

Atrazine movement in a dark red latosol of the tropics.

Atrazine dissplacement was studied in a soll profile as function of water movement and time after herbicide application, taldng into account possible influences of preferential flow on keaching. The experiment consisted of two 7 x 7 m plots of a dark red latosol (Kanduidalfic Eutrudox), located at Pirecicaba, SP, Brazil (22o43'S and 47o25'W), 250 km inside continent, at an altitude of 580 m. One plot was previously treated with 1,000 kg/ha of lime, in order to increase saturation to 88%, and 500 kg/ha of gypsum. Each plot was instrumented with tensiometers, neutron probe acess tubes and soil solution extractors, in order to monitor water and atrazine flows. Atrazine was applied at the high rate of 6 kg/ha of active principllle. Results showed intensiive leaching of atrazine in the whole soil profile, up to the instrumented depth of 150 cm, alredy at the first sampling, seven days after herbicide application. The limed plot showed much higher atrazine leachinng losses than the other plot. The atrazine adsorption capacity of the soll is very low, its maximum value being of the order of 10%, for the 0-15 cm surface layer.

Ocorrência e controle de lesmas do gênero Omalonyx (Gastropoda, Succineidae), pragas de capim-elefante Pennisetum purpureum (Poaceae) em Rio Preto da Eva, Amazonas.

Lesmas do gênero Omalonyx d'Orbigny, 1837 são hermafroditas, herbívoras, de distribuição neotropical e vivem em plantas aquáticas, nas demais vegetações adjacentes e em solo úmido próximo a ambientes de água doce. No presente trabalho reporta-se a ocorrência atípica de O. pattersonae Tillier, 1981 e de Omalonyx sp. em área de terra firme, distante de ambiente aquático.