Marília Alves Brito Pinto

Characterization of soil chemical properties of strawberry fields using principal component analysis

SUMMARY One of the largest strawberry-producing municipalities of Rio Grande do Sul (RS) is Turucu, in the South of the State. The strawberry production system adopted by farmers is similar to that used in other regions in Brazil and in the world. The main difference is related to the soil management, which can change the soil chemical properties during the strawberry cycle. This study had the objective of assessing the spatial and temporal distribution of soil fertility parameters using principal component analysis (PCA). Soil sampling was based on topography, dividing the field in three thirds: upper, middle and lower. From each of these thirds, five soil samples were randomly collected in the 0-0.20 m layer, to form a composite sample for each third. Four samples were taken during the strawberry cycle and the following properties were determined: soil organic matter (OM), soil total nitrogen (N), available phosphorus (P) and potassium (K), exchangeable calcium (Ca) and magnesium (Mg), soil pH (pH), cation exchange capacity (CEC) at pH 7.0, soil base (V%) and soil aluminum saturation(m%). No spatial variation was observed for any of the studied soil fertility parameters in the strawberry fields and temporal variation was only detected for available K. Phosphorus and K contents were always high or very high from the beginning of the strawberry cycle, while pH values ranged from very low to very high. Principal component analysis allowed the clustering of all strawberry fields based on variables related to soil acidity and organic matter content.

Desenvolvimento de mudas de mirtileiro inoculadas com fungos micorrízicos arbusculares

The objective of this study was to measure the effect of inoculation with arbuscular mycorrhizal fungi (Glomus clarum Nicolson and Schenck, Glomus etunicatum Becker and Gerd, Gigaspora margarita Becker and Hall and Scutellospora heterogama Nicolson and Gerd) in seedlings of blueberry cultivars Woodard. The experimental design was a randomized block with five treatments, with four plots per treatment and six plants per plot. Plants inoculated with G. margarita showed greater height and dry weight of roots. The treatments with S. heterogama and G. margarita showed the highest results for the green biomass of roots. The performance was related to the rate of colonization of roots, plants inoculated with G. margarita and S. heterogama, were 48.2 and 45.1%, respectively. For the nutritional contents, plants inoculated with S. heterogama, G. etunicatum, G. clarum and G. margarita provided higher levels of N and P in the shoots.