Resumen en: The aim of this study was a survey of the estimated costs of soil erosion, an issue of fundamental importance in view of the current worldwide discussion...

http://www.redalyc.org/pdf/1802/Resumenes/Abstract_180218547001_2.pdf

Revista Brasileira de Ciência do Solo

Silicon improves seed germination and alleviates oxidative stress of bud seedlings in tomato under water deficit stress.

Soil compaction management and soybean yields with cover crops under no-till and occasional chiseling

Agriculture and livestock integration is a sustainable practice that improves both crop yield and pasture recuperation/formation. However, to achieve success it is important to identify crop cultivars more adapted to intercropping with grasses. Th erefore, the objective was to evaluate nutrient concentration and grain yield of soybean (Glycine max (L.) Merr.) cultivars with diff erent life cycles as aff ected by palisadegrass (Brachiaria brizantha (Hochst. ex A. Rich) Stapf) intercropped in the same furrow at diff erent depths, in a no-till system, as well as dry matter production and protein concentration of palisadegrass pasture. Experiments were performed during two growing seasons, on a Typic Haplorthox, at Botucatu, Sao Paulo State, Brazil. Th e experimental design was a randomized block, arranged in a 2 × 4 factorial scheme, with six replications. Treatments consisted of two cropping systems (sole cropped soybean; soybean and palisadegrass intercropped) and four soybean cultivars (super-early cycle (Monsoy 6101), early cycle (Embrapa 48), normal cycle (BRS 133), and late cycle (Emgopa 313)). Life cycle duration of the soybean had a marked eff ect, and only early cycle soybean were successful intercrops. Intercropping palisadegrass with super-early or early soybean cultivars were viable options to crop-livestock integration, because they did not aff ect both soybean or palisadegrass yield. In addition, with these cultivars, it was possible to cultivate grain and then aft erward more time for cattle (Bos taurus and Bos indicus) grazing in the same area, providing greater revenue compared to sole soybean cropped or in the intercropping with longer cycle cultivars.

An Innovative Crop–Forage Intercrop System: Early Cycle Soybean Cultivars and Palisadegrass

Swine manure is a good nutrient source, but may have a negative impact on the environment when inadequately used. The aim of this work was to evaluate changes in properties of soils under no-till grain production and long-term swine manure fertilization. Soil samples from three representative soils types (Oxisol, Inceptisol and Leptosol) from Western Santa Catarina, Southern Brazil, were collected under no-tillage cultivation and surface application of swine manure for about 15 years and over 20 years. Samples from areas treated with mineral fertilizer and unfertilized controls (under forest vegetation) were also collected from seven soil layers (0-5, 5-10, 10-20, 20-30, 40-50, 70-80, and 100-110 cm) to evaluate soil organic matter content and available P, K, Cu, and Zn. Long-term swine manure application caused nutrient accumulation (P, K, Cu and Zn) in the top soil layer, mainly in the top 5 cm of soil. Soil organic matter was not affected by manure application. In general, the annual manure applications did not affect the chemical properties of the subsoil. In Leptosol and Inceptisol, however, increased P concentrations were found in the 40-50 cm and 70-80 cm soil layers, indicating a greater potential for P loss in these soils. Exchangeable Zn and Cu was accumulated mainly in the top 10 cm of the Oxisol and in the top 20 cm of the Inceptisol and Leptosol. The accumulation of nutrients in the top soil layer (0-5 cm) indicated a greater potential for nutrient loss than in soils treated with conventional mineral fertilizer.

/pdf/atributos-quimicos-do-solo-influenciados-por-sucessivas-1llpp09a3z.pdf

Atributos químicos do solo influenciados por sucessivas aplicações de dejetos suínos em áreas agrícolas de Santa Catarina

Plant growth regulators (PGRs) applied to cotton plants (Gossypium hirsutum L.) can be washed off by rainfall. It is expected that the closer the rainfall to spraying time, the higher the product loss and the higher the amount of product to be reapplied to reach the desired growth rate. The objective of this study was to evaluate the effects of time between rainfall and application of either mepiquat chloride or chlormequat chloride to cotton on plant growth, as well as, estimate the need for PGR reapplication. Cotton was grown in 12-L pots with soil in a greenhouse. PGRs were applied forty days after seedling emergence, when 50% of plants had one pinhead square. Rainfall was simulated 1, 2, 4, 6, or 24 h after spraying. Plant height was measured just before PGR application and then at 3-d intervals for 30 d. At harvest, the number of reproductive branches and structures were counted before dry matter phytomass determination. Both growth regulators reduced cotton dry matter yields regardless of rainfall interval. PGRs controlled excessive plant growth; however, their efficiency was reduced as the time elapsed until rainfall was shorter. Product losses were detected after all rainfall intervals, which, in field conditions would require PGR reapplication. Mepiquat chloride rates to be reapplied after rain were on average 17% higher than chlormequat chloride rates.

http://www.scielo.br/pdf/sa/v67n2/a05v67n2.pdf

Growth regulator losses from cotton plants due to rainfall

Maintaining crop residues on the surface of soils with the possibility of renewing sugarcane fields could be a key factor for improving the structural quality of the soil. The objective of the present study was to assess the structural quality of soil after the use of alternative crops under a no-tillage system in the restoration of a sugarcane field, by the least-limiting water range (LLWR) and the load-bearing capacity (LBC) models. The study utilized a randomized block design in a banded scheme, with six treatments and five replications. Two soil depths were evaluated: 0.15 and 0.25 m. The five crops studied were Crotalaria juncea, C. ochroleuca, Helianthus annuus (sunflower), Glycine max (L.) Merrill (soybean), and Sorghum bicolor (L.) Moench (sorghum), in addition to a fallow treatment. The highest LBC values in the 0.15 m depth were provided by the treatment grouping of soybean–sorghum until the water content reached 0.26 m3 m−3; after this value, the highest LBC values were provided by the C. ochroleuca–C. juncea–sunflower–soybean treatment grouping. In the 0.25 m depth, the highest LBC values were provided by the C. juncea–sunflower–sorghum treatment grouping until the water content reached 0.26 m3 m−3; after this value, the highest LBC values were provided by the fallow–soybean grouping for water content reaching 0.50 m3 m−3. The crops used prior to sugarcane planting modified the physical and water properties of the soil at the two depths evaluated.

Hydrophysical Quality of an Oxisol Under a No-tillage System with Alternative Crops to Renew a Sugarcane Field

The objective of this research was to evaluate shoot growth, nitrogen level and accumulation of millet and black oat plants affected by N doses in sowing The experiment was conducted in greenhouse with a portion of soil classified as a Dystrofferic Red Argissol The treatments consisted of the millet and black oat cultivation in four N doses (0, 50, 100 and 200 mg dm-3) in sowing Fifty days after seedling emergence the shoot dry matter was determined, and also carbon and nitrogen levels Millet shoot dry matter showed higher values as affected by N increasing However, the same behavior Agrarian, v1, n2, p45-57, out/dez 2008 4 6 Agrarian, v1, n2, out/dez 2008 6 did not occurred for the N level in the tissues; In the highest dose, falling tendency for millet and increasing for black oat were observed Early nitrogen fertilization in C3 and C4 species may affect differently plant residues maintenance on soil surface and nutrients release Key-words: cover crops, c/n ratio, no-tillage system

Nitrogen fertilization and quality of pearl millet and black oat residues.

E158 Urinary stone composition analysis – five-year experience of a major Portuguese urological center

The objective of this research was to evaluate shoot growth, nitrogen level and accumulation of millet and black oat plants affected by N doses in sowing. The experiment was conducted in greenhouse with a portion of soil classified as a Dystrofferic Red Argissol. The treatments consisted of the millet and black oat cultivation in four N doses (0, 50, 100 and 200 mg dm-3) in sowing. Fifty days after seedling emergence the shoot dry matter was determined, and also carbon and nitrogen levels. Millet shoot dry matter showed higher values as affected by N increasing. However, the same behavior Agrarian, v.1, n.2, p.45-57, out./dez. 2008. 4 6 Agrarian, v.1, n.2, out./dez. 2008 6 did not occurred for the N level in the tissues; In the highest dose, falling tendency for millet and increasing for black oat were observed. Early nitrogen fertilization in C3 and C4 species may affect differently plant residues maintenance on soil surface and nutrients release. Key-words: cover crops, c/n ratio, no-tillage system.

Adubação nitrogenada e qualidade dos restos vegetais de milheto e aveia preta 1 Nitrogen fertilization and quality of pearl millet and black oat residues

Rodrigo Arroyo Garcia

Papers

Growth regulator losses from cotton plants due to rainfall

Hydrophysical Quality of an Oxisol Under a No-tillage System with Alternative Crops to Renew a Sugarcane Field

Nitrogen fertilization and quality of pearl millet and black oat residues.

E158 Urinary stone composition analysis – five-year experience of a major Portuguese urological center

Adubação nitrogenada e qualidade dos restos vegetais de milheto e aveia preta 1 Nitrogen fertilization and quality of pearl millet and black oat residues