Date of Award
Level of Access Assigned by Author
Master of Science (MS)
Plant, Soil, and Environmental Sciences
Second Committee Member
Third Committee Member
Interest in reduced tillage systems has been increasing and advanced by a need to practice agriculture in a sustainable way to limit environmental degradation. The focus on preserving soil integrity has become commonplace in all scales of agriculture. Recently trends in agricultural production have given rise to numerous small farms centered on local and sustainable farming. In turn, this has led to a growing desire to implement conservation tillage into these systems.
In 2015 and 2016 a collaborative effort between the University of Maine at the Maine Agricultural and Forestry Experiment Station: Highmoor Farm and Cornell University at the Homer C. Thompson Vegetable Research Farm and the Long Island Horticultural Research and Extension Center took place to explore combinations of popular fertility sources available to small-scale organic growers; with the goal of optimizing rates of these amendments in a reduced tillage system.
Multiple combinations with different rates of pre-plant bloodmeal, compost and side-dressed bloodmeal applied by total N were created. Compost and pre-plant bloodmeal were applied either in a band or by broadcasting, side-dressed bloodmeal was always applied as a band. Pre-plant bloodmeal fertilizer was applied at a rate 40 lbs·acre-1 of N at all sites. In the 2016 growing season an additional treatment in Maine included bloodmeal at a rate of 80 lbs·acre-1 of N. Compost was applied at 80 lbs·acre-1 of N at all sites, additional treatments in Maine included compost at 40 and 120 lbs·acre-1 of N as well. Side-dressed bloodmeal at 40 lbs·acre-1 of N was applied mid-season at all sites.
The experiment was set up as a randomized complete block with 4 replications and Honey Bear acorn squash (Cucurbita pepo ‘Honey Bear’) was used as the crop. Fruit number, fruit weight, dry stem weight and petiole %NO3-N data were taken at all sites. Site data was analyzed separately using ANOVA at P3-N. Additionally, %P was analyzed in Maine.
In Maine, compost increased yields in 2015. However, levels exceeding 40 lbs·acre-1 of N were found to provide no additional benefit within the same year. Bloodmeal had no effect on yield in either year of the experiment. In Freeville, bloodmeal increased yields in 2015. Pre-plant applications were found to have a greater effect on yield then mid-season applications. Compost was found to have a negative effect when banded. In Riverhead, the combination of compost with pre-plant and sidedressed bloodmeal produced the greatest yields.
Except for Freeville in 2015, little difference was found when comparing banding or broadcasting of materials. When N was limiting, compost failed to supply N for crop growth even with a C:N ratio lower than 20:1. When P was limiting, compost was able to significantly increase yields. Results from 2015 were not repeated at any site in the 2016 year, possibly due to high levels of background fertility.
Rowley, Nicholas W., "Optimizing Fertilizer and Compost Rates in Organic Reduced Till Agriculture" (2018). Electronic Theses and Dissertations. 2867.