Orchard floor management effects on nitrogen fertility and soil biological activity in a newly established organic apple orchard

The establishment of apple orchards as temperate forest garden systems and their impact on indigenous bacterial and fungal population abundance in Southern Ontario, Canada

“…Our results follow similar trends to the two aforementioned studies regarding positive tree growth with woodchip mulch application. Conversely, the forest garden-based treatments, which had leguminous and non-leguminous perennial cover crops, saw no comparable disadvantage to tree growth, as Hoagland et al (2008) did. Perhaps the spacing of supportive plants outside of the establishing apple tree root zone (60 cm beyond roots at planting) and woodchip mulch application was an effective mix of understory management techniques that mitigated competition.…”

“…Similarly to the abovementioned study, this may have been a result of the larger amount of wood chips in the FGS-based treatments, which were used to mulch all the plants in the entire plot compared with only around the apple tree in the G and GC treatments. Hoagland et al (2008) also found that 15 cm of woodchip mulch in newly established apple orchards resulted in increased tree growth. Mulched treatments caused a 298% increase in TCSA, compared with cultivated, living leguminous mulch and living non-leguminous mulch treatments, which had 285, 180 and 196% increases in TCSA, respectively, after 1 yr (2005)(2006).…”

“…Schreb. ), creeping red fescue (F. rubra L.) and perennial rye grass (Lolium perenne L.), was hand broadcast in spring each year for better establishment and a 15 cm layer of coarse softwood chip mulch was laid only around the root zone of the apple tree (0.75 m 2 ); (2) GC: same as G with 2.7 kg (Hoagland et al, 2008) of organically certified turkey litter compost (Cold Springs Farm, Guelph, Ontario, Canada; 1.02% N, 19.06% OM, 1.31% P, 0.72% K and a C:N ratio of 10.6) applied around the root zone of the apple tree as a single application in the first year ( (Shortt and Vamosi, 2012), and a 15 cm layer of coarse softwood chip mulch around all plants (2.25 m 2 ) (Hoagland et al, 2008); and (4) FGSC: same as FGS with 2.7 kg of organically certified turkey litter compost applied around the root zone of the apple tree as a single application in the first year. The plants in the forest garden-based treatments were chosen for their known functions, based on anecdotal and academic sources, and how these species might contribute to the ecology of this production system.…”

“…Also, in approximately 50% of New York, USA, fruit growers experience replant disease, which results in reduced tree health and, depending on the region and practices used, develops from a combination of varying levels of nutrient imbalances, soil compaction, the presence of particular fungi, bacteria, and nematodes, and herbicide residue buildup (Leinfelder and Merwin, 2006). Hoagland et al (2008) studied multiple methods of organic orchard ground management systems ranging from cultivation with compost amendments, to wood chip and living mulches. They found that increased compost additions (5.4 and 8.1 kg) with cultivation as a form of short-term nutrient supply did not change the soil microbial activity (nor did it affect tree growth) compared with the control treatment with a lower compost application (2.7 kg), whereas living mulch treatments (mix of broadleaf and grass species) measured significantly higher in dehydrogenase activity, C mineralization, CO2 production and nematode numbers.…”

“…These practices also resulted in increased soil nutrients and tree growth. Hoagland et al (2008) discussed a need for management succession strategies that implement living understories in a way that reduces competition to the main crop during sensitive establishment growth years and that matures into self-sufficiency. This concept is similar to FGSs and tends to implement diverse plant structures, species, functions and interactions.…”