The use of guava seedlings with adequate nutritional status determines the success of an orchard installation. This study was conducted to determine plant growth and macronutrient accumulation in herbaceous seedlings of two guava cultivars. The experiment was arranged in a completely randomized design in split-plots with three replications. Plots consisted of the two guava cultivars (Paluma and Século XXI) in nutrient solution and the sub-plots were the seven sampling dates in a 120 day period. Plant height, number of leaves, stem diameter, […]

Restinga is a typical vegetation on quartzitic, sandy, nutrient-poor parent materials along the Brazilian coast. Soils under restinga vegetation on the Ilha do Cardoso (SP) were studied to understand their genesis and to improve the Brazilian Soil Classification System (SiBCS). Thus, a physical, chemical and detailed morphological characterization was carried out. The results evidenced aquic, sandy, very acid soils with variable organic matter content, in which podzolization is the main pedogenic process. Sulphidric materials also occur due to the influence […]

This study aimed to evaluate the effect of coffee planting spacing on soil carbon and nitrogen storage and on the contents and distribution of organic matter fractions (light and heavy) of a dystroferric Red Latosol (Oxisol). An experiment installed 11 years ago on an experimental farm of EPAMIG in Machado (Minas Gerais State, Brazil) was evaluated. The treatments consisted of the combination of four spacings between rows (2.0, 2.5, 3.0 and 3.5 m) with three spacings between plants (0.5, 0.75 and […]

Soil physical quality is essential for plant growth and sustainable agricultural systems. This study aimed to evaluate the efficiency of the least limiting water range (LLWR) to monitor soil compaction and soil physical quality for soybean, without and with irrigation. The study was carried out in an clayer Red Latosol (Oxisol) (21 ° 14 ‘ 53 ” S; 48 ° 17 ‘ 20 ” W; 540 m asl). The experiment was entirely randomized, in a 6 x 2 factorial scheme, with four repetitions. The compaction treatments were: T1 = without compaction; T2 = 1 pass of a 4 t […]

Soil suction has been regarded by soil scientists as an aspect of increasing importance and has been used as an important source of information in agriculture since early last century. Its knowledge helps improve human actions not only in aspects relating to vegetation and agriculture, but also concerning slope stability. Increasingly sophisticated tensiometers have been designed to measure soil suction. This study describes the state of the art in the evolution of tensiometers, aside from the development of a tensiometer […]

The advance of the agricultural frontier, characterized by the conversion of natural ecosystems into cultivated areas, was intensified in the last decades. Most of the practices used to manage soils cause changes in the soil quality and soil organic matter (SOM) dynamics. Studying the impact of different management systems is essential to choose the most adequate soil management practices. This study aimed to evaluate different SOM fractions and carbon and nitrogen storage of a very clayey typic dystroferric Red Latosol […]

Restinga is a typical vegetation on quartzitic, sandy, nutrient-poor parent materials along the Brazilian coast.. Podzolization is the main pedogenic process in restinga soils and Spodosols and Quartzipsamments with incipient podzolization are the most common soils. Podzolization is frequently studied in cold climate regions, while mineralogical studies of Spodosols in tropical climate on quartzitic parent material are scant. In this work, soils under restinga vegetation on the Ilha do Cardoso-SP, Brazil were studied to identify the mineralogical assembly of silt […]

Endophytic diazotrophic bacteria are capable of promoting maize growth through biological nitrogen fixation (BNF) or by the production of plant hormones. The aim of this study was to characterize diversity of endophytic bacteria in maize at sites with different climate and soil conditions in Rio Grande do Sul, Brazil. A PCR-RFLP approach and sequence analysis of nifH Cluster I clone libraries were used to assess diversity in maize plants. The Shannon-Weaver and Equitability indices were calculated to estimate the diazotroph […]

Nitrogen is an essential nutrient for common bean. However, there are still doubts about which source and level should be used to supply crops with this nutrient via sidedressing application in no-tillage systems. The objective of this work was to evaluate the influence of sources and doses of sidedressed nitrogen on common bean nutrition and grain yield (Phaseolus vulgaris L.) under no-tillage, on a Rhodic Nitisol. It was used a randomized complete block design with four replications, in a 2×4 […]

Presently, approximately 60 % of the grain crop area in Paraguay is under no-till (NT). With the expansion of NT in the country, some doubts were raised with respect to the obsoleteness of fertilizer recommendations, especially regarding phosphorus (P). The last P fertilizer recommendation had been established for conventional soil tillage system 15 years earlier. The main objective of this work was to update phosphate fertilizer recommendations for wheat, corn and soybean under NT. Seven different locations in eastern Paraguay were evaluated […]