Ten years of organic fertilization in peach: effect on soil fertility, tree nutritional status and fruit quality.

摘要

The objectives of this experiment were to evaluate the long term (10 years) effects of organic fertilization on soil fertility, tree performance and fruit quality in a commercial peach orchard. Since planting in 2001, trees were subjected to the following treatments: (i) unfertilized control, (ii) mineral fertilization including P (100 kg ha-1) and K (200 kg ha-1) applied at planting and N (70 kg ha-1 for the first three years and then 120-130 kg ha-1) split in two applications at 40 days after full bloom (60%) and in September (40%) and repeated yearly; (iii) cow manure supplied at planting (10 t dw ha-1) and then, from the 4th year at the rate of 5 t dw ha-1 per year in spring; (iv) compost supplied at planting (10 t dw ha-1) and then, from the 4th year at the rate of 5 t dw ha-1 per year in spring; (v) compost supplied at 5 t dw ha-1 y-1, and (vi) compost added at 10 t dw ha-1 y-1, with both treatments (v) and (vi) split as described for treatment (ii). In 2010, nitrate-N soil concentration was increased by the application of compost at 10 t ha-1 and mineral fertilizer; ammonium-N soil concentration was increased by the application of compost at the highest rate only at the beginning of the season, when soil moisture, due to heavy rains, was near field capacity. Microbial C was increased by application of compost, but not by cow manure. Tree yield was not affected by treatments; however, fruit size was increased by mineral and high rate compost fertilizations. Leaf concentrations of chlorophyll and N were increased by the application of compost at the highest rate and mineral fertilizer.