- Agronomic: other, grass (misc. perennial), hay
- Fruits: apples
- Animal Production: feed/forage
- Crop Production: cover crops, nutrient cycling, organic fertilizers, tissue analysis
- Pest Management: allelopathy, biological control, cultural control, integrated pest management, mulches - living, mulching - vegetative, weed ecology
- Production Systems: organic agriculture
- Soil Management: green manures, nutrient mineralization, soil chemistry, organic matter, soil quality/health
A certified organic apple orchard was established to study the interaction of ground cover management and nutrient sources on orchard performance in the southern region and effects on soil properties and nutrient content, and tree nutrient status. Trees received one of four ground cover management treatments as an under canopy mulch: 1) urban green compost (GC), 2) refuse wood chips (WC), 3) shredded commercial paper (SP), and 4) mow-and-blow vegetation (MB). Across all ground covers, one of three nutrient source treatments was applied: A) control – the ground cover treatment provides nutrients (NF), B) composted poultry litter (PL), C) a commercial pelletized, poultry-based product (CF). Significant main effects of treatments and interaction effects were presented. The MB treatment plots showed slightly higher soil water tension during growing season. GC treated trees had increased soil organic matter, pH, and electrical conductivity (EC) at 0 to 10 and 10 to 30 cm depth from March to September. GC treated plots had highest [NO3-N] in soil solution in July and September, but SP treated plots had lowest concentration. GC treated trees had the highest [NO3-N], [P], [K], [Ca], [Mg], [S], and [B] at 0 to 10 cm and 10 to 30 cm soil depth during March and May. SP treated trees had the highest soil [Na] and [Mn] at both depths during March and May. Nutrient source treatment effects varied for soil nutrition during March and May. GC, WC, and MB treated trees had significantly higher foliar [N] regardless of nutrient sources, but foliar [P], [K], and [Ca] were lowest in those ground cover systems compared to SP treated trees in August. SP treated trees had deficient foliar [N] based upon conventional orchard standards. GC treated trees had significantly higher foliar [Mg]. There were no nutrient source effects on foliar [N] and [Ca]. CF and PL treated trees had higher foliar [Mg] but lower foliar [P] and [K] compared to NF treatments. GC with PL treated trees had higher SPAD chlorophyll value from May to September. Measured soil and foliage treatment response variables were more affected by ground cover treatments than nutrient source treatments in the first two years.
Project objectives:div style="margin-left:1em;">
1. To evaluate seasonal soil and foliar nutrient concentrations, and tree performance when grown under different three fertilizers with four groundcover management systems in the southern region of the US.
2. To evaluate organic orchard management systems for tree growth during orchard establishment