Calagem e adubação do maracujazeiro-doce.

ABSTRACT: The sweet passion fruits is a native species of Brazil. It is very well adapted to tropical regions, and can be found growing in wild conditions or cultivated by small farmers in many regions. It is consumed mainly as a fresh fruit, splitting with a knife in two parts and using a spoon to collect the pulp with the seeds. The concentrated juice, easily extracted from the pulp, can be used to make juice, ice-cream and deserts. Many small farmers grow sweet passion fruit as an ornamental plant, particularly because of the beauty flowers and colored fruits. In additon it is considered as a medicinal species to treat stress, anxiety and sleeplessness. The ofter of fresh sweet passion fruit in most fruit and grocery stores is still very limited, and prices are very high. The main purpose of this paper is to collect the most important research results regarding practices used to correct the soil acidity and to supply nutrients to improve the production systems of sweet passion fruit.bitstream/CPAC-2009/27307/1/doc_140.pd

Manejo da fertilidade do solo no pre-plantio e plantio do cafeeiro

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Irrigação do cafeeiro no cerrado: estratégia de manejo de água para uniformização de florada.

ABSTRACT: The objective of this research was to define irrigation scheduling for coffee trees in the brazilian Cerrado region to optimize yield and coffee grain quality. The experimental treatments were: a) irrigation all over the year (RH1), suplemental water application after blossoming induced by rain (RH4), stop water application, at the harvesting time from June 15 to end of August until leaf water potential measured at pre-dawn reached - 2.0 MPa (RH3) and - 3,4 MPa (RH4) and rainfed crop. The soil water content was monitored by using a profile probe of 1 m. Water was applied to fill the soil profile of 0.40m until field capacity (-0,0008 MPa) as soil water depletion reached 50% of available soil water. The results shows that stopping irrigation from June 15 to end of August, until leaf potential, measured at pre-drawn, reached value of - 2.0 MPa resulted in just on uniform blossoming period, more than 80% pf mature grain at harvesting time and yield of 4.200 kg.ha(-1) of peeled coffee grain in the last three comercial harvesting.bitstream/CPAC-2009/27309/1/comtec_122.pd

Nutrient Release, Plant Nutrition, and Potassium Leaching from Polymer-Coated Fertilizer

ABSTRACT The increase in food consumption and limitations in food production areas requires improved fertilizer efficiency. Slow- or controlled-release fertilizers are an alternative for synchronizing nutrient availability with the plant demands, reducing losses to the environment. The aim of this study was to evaluate the efficacy of polymer-coated KCl compared with conventional KCl. The products were incubated in soil under controlled conditions to evaluate the time required for nutrient release. A greenhouse experiment was performed with corn plants in pots with loamy sand- or clay-textured soil types to evaluate plant nutrition and losses due to leaching. The K application rates were 0, 18, 36, and 54 mg dm-3. The pots were irrigated, and the percolated liquid was collected. The plants were harvested 30 days after sowing to quantify dry matter (DM) and its K content. In the incubation study, the K release from the coated fertilizer was found to be 42 % over 154 days. The data were fit to a linear function from which a period of 315 days was estimated as required for the release of 75 % of the nutrient. Meanwhile, conventional KCl releases 85 % of the K nutrient in the first 48h. In the cultivation of plants in pots, the coating reduced K losses due to leaching in the loamy sand soil; however, only the application rate of 54 mg dm-3 promoted DM production equivalent to conventional KCl. It is possible that the need for K in the early stages of corn development was not met by a coated KCl