Interaction between farming type, nutrient uptake and plant material in strawberry tree fruit production and quality

Strawberry tree is a Mediterranean species, tolerant to drought stress and forest fire. These qualities make it relevant for agroforestry systems. Fruits are suitable for fresh fruit consumption, brandy and other uses. To identify the nutrient cycle and its relationship with fruit production, soil samples, organic layers, leaves and fruits were collected for analysis in two farming types: natural regeneration and orchard, containing trees of 22 and 7 years old, respectively. In the orchard, two trials were established: Leptosols seedlings and Cambisols, where the fertilization effect and the vegetal material (seedlings vs. clonal plants) were evaluated. The soil showed acidic pH (5.0-5.4). The highest organic layer content was observed in the natural regeneration regime (7.6 t ha(-1)), in contrast to the orchard trials (2.3 and 4.8 t ha(-1)). Natural regeneration also showed higher values of K2O (119.1 vs. 91.5 and 84.4 mg kg(-1) in the orchards). The nutrient content in the leaves occurred in the following decreasing order: macronutrients, N > Ca > K > S > Mg > P; micronutrients, Mn > Fe > Zn > B > Cu. Higher fruit production, which is linked with greater nutrient concentration, had the following decreasing pattern: K > Mg > Ca > P > N > Fe > Zn, while the concentrations of B, Mn and Cu were similar. The first orchard, which had significantly lower levels of organic layer, pH, Ca2+, Mg2+, Zn and Mn, showed lower fruit production (P<0.05). The highest fruit production (1.7 t ha(-1)) was recorded in clonal plants with fertilization. In all conditions tested, average values of total soluble solids (TSS) higher than 22 degrees Brix were observed. Fruits of clonal plants showed lower TSS values, demonstrating accordingly that fertilization is desirable to compensate the greater amount of nutrients uptake linked to fruit production. Our results show that establishing clones adapted to the agro-ecological conditions, by carrying out fertilization and preserving the soil organic layers, contributes to agroforest system sustainability, fruit quality and production.

Automated summary

The study results show that planting clones adapted to the agroforest system conditions, through fertilization and preserving soil organic layers, contributes to the sustainability, fruit quality, and production of the agroforest system.