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Manuck, Christine Marie

Plant and Soil Science

2006

MS

Application of synthetic fertilizer through banding is a fertilizer application technique capable of reducing overall fertilizer use expenses and nutrient loss to the local environment. Modification of this technique to incorporate dairy manure compost, rather than synthetic fertilizer, can provide an outlet for local compost supplies and reduce the overall volume of compost that vegetable growers need to purchase. Fertilizing using banding techniques makes use of a plant's capability to exploit nutrient dense regions to obtain adequate nutrients. We examined the ability of plant root systems to utilize and manipulate the nutrient dense patches created by bands of compost and examined the root responses to different media types in non-nutrient limiting conditions. A greenhouse container study of the ability and effectiveness of bands of compost to provide adequate fertilizer was performed using young tomato (Lycopersicon esculentum Mill. cv Early Girl) and sweet corn (Zea mays L. cv. Temptation) plants. Plants received compost banded at a rate of 20 tons·acre⁻¹, 40 tons·acre⁻¹, or 80 tons·acre⁻¹, broadcast at the rate of 40 tons·acre⁻¹, or 150 ppm 17-4-17 liquid synthetic fertilizer. While neither tomato nor sweet corn produced the level of growth that was expected, sweet corn plants demonstrated a greater likelihood of root proliferation than tomatoes. This suggested that field grown sweet corn plants may be more likely to effectively use bands of compost than tomato plants.
Root growth, plant biomass, and marketable yield were evaluated in response to varying concentrations of banded compost in a field experiment using sweet corn cv. Temptation. Sweet corn seedlings were transplanted at two different field sites differentiated by soil type. Nutrition schemes used were: banding rates of 20 tons.acre⁻¹, 40 tons·acre⁻¹, and 80 tons·acre⁻¹, compost broadcast at the 40 tons·acre⁻¹ rate, and 160 lbs·acre⁻¹ of banded 10-10-10 synthetic fertilizer. Fertilizer application method significantly impacted root growth but not plant marketable yield. Plants receiving compost banded at the 40 tons·acre⁻¹ or 80 tons·acre⁻¹ rates had significantly lower root length and surface area than other treatments, yet marketable ear yield did not suffer as a result. This indicates that increased root proliferation is not essential to ear yield, and that sweet corn can be adequately fertilized through bands of compost. Plant growth and ear production differences between field sites indicate the potential for compost banding to be less effective on sites that have rapid drainage or low initial fertility. Identifying whether root morphological changes occur in response to changes in nutrient density or in response to differences in media physical properties can provide insight into the architectural responses measured in response to bands of compost. Sweet corn cv. Temptation seedlings were transplanted into containers filled with one or two media types. Media combinations were: Fafard 3B and sterile sand, Fafard 3B and a compost and sand mixture, sterile sand and a compost and sand mixture, and sterile sand and compost. Two treatments were established with entirely sterile sand or Fafard 3B. All media treatments received adequate levels of 17-4-17 synthetic fertilizer such that nutrients were non-limiting. Root architecture measurements proved that when nutrients are non-limiting root length, surface area, diameter, and dry weight do not significantly vary in roots growing between any of the two media types tested. This indicates that root architecture observed between two media types in nutrient limiting conditions may be due to changes in nutrient level, rather than differences in the soil physical composition.