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ARS Home » Pacific West Area » Kimberly, Idaho » Northwest Irrigation and Soils Research » Research » Research Project #434850

Research Project: Long-Term Impacts of Manure Application on Production of Potato

Location: Northwest Irrigation and Soils Research

Project Number: 2054-12000-011-13-S
Project Type: Non-Assistance Cooperative Agreement

Start Date: Jun 1, 2018
End Date: May 31, 2019

Determine the effects of manure application rates and timing (annual or biennial; few years or several years of manure application), on yield potential, tuber quality, soil quality, disease pressure, insect pressure and nutrient uptake.

This 8-year study is currently being conducted on two adjacent 2.5 acre sized sprinkler irrigated fields at the USDA ARS in Kimberly, Idaho. The selected crop rotation for field #1 is wheat-potatoes-barley-sugar beets, and will therefore be planted to potatoes in 2018. The selected crop rotation for field #2 is barley-sugar beets-wheat-potatoes, and will therefore be planted to potatoes in 2020. Treatments will include timing (manure application every year or every other year (before grain)) and rate (8, 16, and 24 ton/acre, dry weight basis). Additional fertilizer treatment (chemical fertilizer applied at agronomic rates based on Cooperator fertilizer guides) and a control treatment (no nutrient source applied) will also be included, for a total of 8 treatments per field (2 timings x 3 rates) + 1 fertilizer trt + 1 control trt). Treatments will be replicated 4 times in a randomized complete block design, for a total of 32 treatments per field. The manure source is a partially dried dairy manure that has been stockpiled at least one year, representing a dairy manure source that is commonly applied to wheat, barley, potato, and sugar beet fields in Southern Idaho. Treated Russet Burbank seed will be planted into field #1 in late April 2018. Response variables will continue to include soil tests, petiole tests, plant and tuber disease analysis, and whole plant tissue analysis. Cooperator will evaluate soil samples for soil borne potato diseases at three sampling events throughout the growing season in 2018. Targeted soil borne diseases will include Rhizoctonia, Black Dot, and pythium. These diseases will be analyzed using DNA extraction equipment in Cooperator's program. Plant ratings for rhizoctonia, stem canker, and black scurf will be conducted at two evaluation events over the growing season by Cooperator's program. Disease pressure will be monitored throughout the growing season and at harvest. Cooperator will visually rate 50 tubers from each plot for wireworm damage by counting the number of feeding scars per tuber in potato production years of the study. Cooperator is targeting wireworms, as their populations have been seen to increase with increasing soil organic matter levels. Cooperator will evaluate soil pre-plant soil samples for nematodes. Cooperator will conduct quality assessments on selected harvested tubers from each plot in potato production years of the study. Quality parameters will include internals, fry color, presence of sugar ends, specific gravity, and sugar content.