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a b s t r a c tPlant analysis plays a major role in fertilizer recommendations for perennial tree crops and vines. Plant analysis, however, does not quantify the rate of nutrients to apply. The approach developed in this work takes into account the content of the nutrients in grapevine parts and their dynamic within the plant to assist in the estimation of the amount of fertilizer to apply. Groups of three vines were cut at ground level on four different dates from September 14th to November 28th. On the first sampling date the vines were separated into trunk, cordons, canes, leaves and clusters for determination of dry matter content and elemental composition. On the following dates the vines were separated into the plant parts that were still present, since the clusters were only present on the first sampling date and the leaves on the first two. To assess the mobility of nutrients within the plant, samples of phloem vessels and sawdust of the entire trunk were taken as well as samples of chlorotic and green leaves. Nitrogen (N), potassium (K), phosphorus (P) and boron (B) showed mobility within the plant whereas calcium (Ca) and magnesium (Mg) did not. The removal of nutrients in clusters is critical for estimating N and K fertilizer rates. Clusters removed 19.9 kg N ha −1 and 28.7 kg K ha −1 . In the case of N, it is also important to assess the system's ability to recycle the nutrient contained in the leaves and canes which amounted to 49.4 kg N ha −1 . Phosphorus, calcium and magnesium applications might not justify being taken into account in the annual fertilization plan. Thus, the establishment of the fertilization programme should be a nutrient-specific exercise which takes into account all sources of information, including target yield and nutrient content in clusters, the vineyard management strategies influencing nutrient use efficiency from fallen leaves and prunings and soil testing and plant analysis.

The adoption of a sustainable soil management system is essential for the steep slopes and low fertility soils still supporting rainfed olive orchards in the Mediterranean basin. The effect of the soil management on olive yield, tree nutritional status and soil fertility was studied in a rainfed olive orchard located in NE Portugal that had been managed since its earliest days as a sheep-walk. In 2001, three different soil management systems were established: Sheep-walk, in which the vegetation was managed with a flock of sheep; Tillage, where the vegetation was controlled by conventional tillage; and Glyphosate, where a glyphosate-based herbicide was applied. The soil management systems had a pronounced effect on olive yield. The accumulated olive yields between 2002 and 2011 were 187.2, 142.9 and 89.5 kg tree-1, respectively in the Glyphosate, Tillage and Sheep-walk treatments. However, the effect of soil management on tree nutritional status was not so clear. On the other hand, the pools of organic carbon and N in the soil, and also the soil available N and phosphorus (P), were found to be less in the Glyphosate and Tillage treatments in comparison with the Sheep-walk. In these soils, N appeared as a much more limiting factor for crop growth than P. In rainfed orchards, the tolerance to herbaceous vegetation appears to be a determining factor in sustainability, which regulates annual crop yields and soil fertility. The higher the tolerance to herbaceous species, the lower the olive yields, but the better are the soil fertility parameters.

No abstract

European chestnut is the most important cash crop in the highlands of NE Portugal. However, limited data on cropping technique are available to help farmers make decisions. This work is motivated by the lack of data related to chestnut response to fertilizer application. It reports results from a field fertilization trial consisting of the application of a combination of lime (L), nitrogen (N), phosphorus (P), potassium (K), and boron (B), namely LNPKB, NPKB, -NPKB, N-PKB, NP-KB, and NPK-B. Seedlings of chestnut were planted in June 2013 and grown for four growing seasons. Plant height, trunk diameter, and pruning wood were assessed every year and used as indicators of tree crop growth. Elemental leaf analysis and other tools [SPAD-502 chlorophyll meter; Field Scout CM 1000 NDVI (normalized difference vegetation index) meter, and the OS-30p+ fluorometer] were used to assess plant nutritional stresses. In January 2017 soil samples were collected at three depths (0-5, 5-10, and 10-20 cm) to determine several soil fertility parameters. The nonapplication of K and B reduced the tree crop growth and pruning residues. Leaf analysis revealed leaf K and B concentrations respectively in the NP-KB and NPK-B treatments to be in the deficient range previously established for chestnut. SPAD readings and NDVI detected the reduced availability of N associated with the -NPKB treatment but not the reduced plant growth associated with NP-KB or NPK-B treatments. The dark adaptation protocols of F V /F M , F V /F 0 , and OJIP measurements performed with the OS-30p+ fluorometer failed to diagnose the nutrient stresses detected by leaf analysis or the reduction in plant growth.