FOLIAR COMPOSITION OF Eucalyptus urograndis IN TWO SITES FERTILIZED WITH N, P AND K IN SOUTHERN BRAZIL

The leaf composition has been used as a tool in establishing the nutritional diagnosis and evaluation of the effectiveness of the use of nutrients. This knowledge is still scarce in subtropical conditions of cultivation. In this sense, the study aims to evaluate the effect of N, P and K fertilization on leaf concentration of Eucalyptus urograndis. The experiments were installed in the Oxisols of the sandy-loam texture, in the counties of Jaguariaíva and Ventania, state of Paraná. In the N and P experiments, the following doses: 0; 30; 60; 120 and 240 kg ha-1 of N and P2O5; and 0; 35; 70; 140 and 280 kg ha-1 K2O, split in four applications: during planting and side dressing at 3, 9 and 12 months of age. The response was evaluated according to the nutritional status of the plants at 12, 24 and 36 months, by foliar concentration. It also evaluated levels of K deficiency plant through visual and chemical analysis. The application of N and P did not result in alteration in the leaf contents of the same in all evaluated periods and in the two regions, with a slight decrease in the concentrations with time. A different effect occurred with K at the Jaguariaíva site, which altered its foliar concentration at the 24th and 36th month, and increased foliar concentrations with time. These effects demonstrate that foliar diagnosis, through foliar concentrations, may present limitations of interpretation and should not be evaluated separately for fertilization recommendation.

Foliar indices for carrot crop using the compositional nutrient diagnosis method1

ABSTRACT Carrot has a high yield potential, which requires an adequate and adaptable nutritional management, according to the needs and demands of each crop. Foliar diagnosis is a tool for adjustment and constant improvement of crop fertilization programs. This study aimed to determine leaf indices and reference values using the compositional nutrient diagnosis (CND) method, at three phenological stages of carrot crops [40 and 70 days after sowing (DAS) and at harvest]. In order to calculate the CND method, a database was created with leaf contents of the nutrients N, P, K, Ca, Mg, S, B, Cu, Mn and Zn and root yields, in commercial carrot crops. The nutrient limitation order was generated according to the fertilization response potential. At 70 DAS and at harvest, Mg and Mn were the most limiting nutrients by deficiency, while Zn was the most limiting by excess at 70 DAS, and P and Ca were the most limiting by excess at harvest. The results indicate that the foliar diagnosis performed with the CND method is only effective for the correction of nutritional disturbances in subsequent crops.

Dinamika Kepemilikan Perkebunan Kelapa Sawit Di Provinsi Riau Sumatra Indonesia

Smallholder’s plantations represent 44% of oil palm in Indonesia, and they were known to have agronomic performance much lower than Estate ones. So there is large room for increasing the yield with sustainable cropping system. To better understand the heterogeneity of smallholder’s plantations, an agricultural diagnosis has been implemented in a specific place, Riau Province of Sumatra. This study led to well characterize the dynamics of plantation in the region and the diversity of rationalities. Among eight existing types of smallholding plots, there were only three types with yield hardly lower than those of the estate plantations. This reinforced the interest to implement diagnosis through the nutritional status of palms using data from foliar diagnosis and soil analysis. Key words : dynamic of plantation, palm oil, smallholders, Sumatra