Arsenic toxicity in Acacia mangium willd. and mimosa Caesalpiniaefolia benth. seedlings
01/Oct/2013
Acacia mangium and Mimosa caesalpiniaefolia are fast-growing woody fabaceous species that might be suitable for phytoremediation of arsenic (As)-contaminated sites. To date, few studies on their tolerance to As toxicity have been published. Therefore, this study assessed As toxicity symptoms in A. mangium and M. caesalpiniaefolia seedlings under As stress in a greenhouse. Seedlings of Acacia mangium and M. caesalpiniaefolia were grown for 120 d in an Oxisol-sand mixture with 0, 50, 100, 200, and 400 mg kg-1 As, in […]
Rates of sewage sludge composted in the zoysiagrass sod production
01/Oct/2013
The efficiency of nitrogen fertilization for sod production can be increased by using slow-release sources such as sewage sludge compost, which, due to its characteristics can be a substitute of part or all inorganic fertilization for grass. No results were found for the use of sludge compost in sod production in Brazil. This study evaluated the effect of rates of sewage sludge compost on the production of zoysiagrass. Treatments consisted of five rates of composted sewage sludge compost (0, 12, […]
Effects of cover crops, soil management and nitrogen rates on nutritional and agronomic attributes of maize
01/Oct/2013
Research has investigated the best nitrogen rate for maize under the most diverse types of soil management. The aim of this study was to evaluate the influence of cover crops, soil management and topdressed N rates on the dry matter production, nutritional status, plant lodging, plant height and first-ear insertion of maize. Field experiments were carried out in Selvíria, Mato Grosso do Sul State, Brazil, in the growing seasons of 2009/2010 and 2010/2011, on a clayey Rhodic Haplustox (20o 20′ […]
Mineralization of organic phosphorus in soil size fractions under different vegetation covers in the north of Rio de Janeiro
01/Oct/2013
In unfertilized, highly weathered tropical soils, phosphorus (P) availability to plants is dependent on the mineralization of organic P (Po) compounds. The objective of this study was to estimate the mineralization of total and labile Po in soil size fractions of > 2.0, 2.0-0.25 and < 0.25 mm under leguminous forest tree species, pasture and “capoeira” (secondary forest) in the 0-10 cm layer of a Red-Yellow Latosol after 90 d of incubation. The type of vegetation cover, soil incubation time […]
Photosynthesis rate, chlorophyll content and initial development of physic nut without micronutrient fertilization
01/Oct/2013
Few studies in Brazil have addressed the need for micronutrients of physic nut focusing on physiological responses, especially in terms of photosynthesis. The objective of this study was to evaluate the effects of omission of boron (B), copper (Cu), iron (Fe), manganese (Mn) and zinc (Zn) on Jatropha curcas L.. The experimental design was a randomized block with four replications. The treatments were complete solution (control) and solution without B, Cu, Fe, Mn, and Zn. We evaluated the chlorophyll content […]
Effect of harvest residues management, soil tillage and fertilization on eucalyptus productivity
01/Aug/2013
Forestry companies have become increasingly concerned about the adoption of practices based on the conservation of soil and water. Thus, this study aimed to assess the impact of crop residue management, tillage and the use of industrial wastes on soil fertility and productivity of eucalyptus. The experiment started after clear-cutting of a commercial plantation of Eucalyptus grandis and the harvest residues were managed differently (removal of all residues; removal of bark and branches with diameter > 3.0 cm; and maintenance […]
Ammonia volatilization from coated urea forms
01/Aug/2013
Nitrogen fertilization is a major component of the cost of agricultural production, due to the high cost and low efficiency of fertilizers. In the case of urea, the low efficiency is mainly due to losses by volatilization, which are more pronounced in cultivation systems in which plant residues are left on the soil. The objective of this work was to compare the influence of urea coated with sulfur or boric acid and copper sulfate with conventional N fertilizers on N […]
Loss of ammonia from nitrogen fertilizers applied to maize and soybean straw
01/Aug/2013
In Brazilian agriculture, urea is the most commonly used nitrogen (N) source, in spite of having the disadvantage of losing considerable amounts of N by ammonia-N volatilization. The objectives of this study were to evaluate: N lossby ammonia volatilization from: [urea coated with copper sulfate and boric acid], [urea coated with zeolite], [urea+ammonium sulfate], [urea coated with copper sulfate and boric acid+ammonium sulfate], [common urea] and [ammonium nitrate]; and the effect of these N source son the maize yield in […]
Development of jatropha seedlings under saline irrigation
01/Aug/2013
The use of saline irrigation water is an important alternative in view of the lack of good water quality throughout the world. The water requirement of jatropha (Jatropha curcas L.) is low, and the species survives and produces satisfactory yields in low-fertility soils. However, yields are higher in irrigated crops, indicating the need of studying the possibility of using saline irrigation water. This study aimed to evaluate the effect of different salinity levels of irrigation water on the morphological and […]
Compaction of an Oxisol and chemical composition of palisadegrass
01/Aug/2013
Compaction is an important problem in soils under pastoral land use, and can make livestock systems unsustainable. The objective of this research was to study the impact of soil compaction on yield and quality of palisade (UROCHLOA BRIZANTHA cv. Marandu). The experiment was conducted on an Oxisol in the State of Mato Grosso, Brazil. Treatments consisted of four levels of soil compaction: no compaction (NC), slight compaction (SC), medium compaction (MC) and high compaction (HC). The following soil properties were […]