Field Crops Production and Pest Management

Organic Fertility Recommendations

Research-based fertility recommendations for organically approved fertilizers and soil amendments to build soil fertility levels are very limited. In organic production systems, crop responses to fertility amendments have been difficult to predict, both because organic amendments behave differently from mineral fertilizer, and because nutrients from fertilizer cycle differently in organically managed soils.

This project is a collaboration among a farmer, Klaas Martens of Penn Yan, Thomas Björkman of Cornell's Department of Horticultural Sciences in Geneva , and Dave Hoffman of the crop consulting firm, Agricultural Consulting Services in Rochester . In order to study the systemic effects, we have enlisted the Soil Health Program Work Team to include the site in their project. Major contributors from that program are George Abawi, Carol MacNeil, Harold Van Es and Bob Schindelbeck. In addition, we have established a satellite site for the Organic Farming Systems Comparison, with Chuck Mohler contributing to analysis of weed responses.

Because the fertility treatments have diverse impacts on the production system in both the short and long term, a systemic and long-term approach is necessary. We are studying the effect of organic and soluble fertilizer application rates on crop response, pollution risk, and soil health.

The specific goals are:

•  Determine the effect of organic fertilizer type and application rate on crop growth and yield

•  Identify kinetics of nutrient availability following compost additions.

•  Identify effect of organic fertilizer type and application rate on soil health

•  Provide grower recommendations for appropriate rates for organic mixed-crop farms.

•  Identify rates that result in pollution risk.

•  Test whether there is a threshold initial application rate for enhancing mineralization.

**Thomas Björkman, Associate Professor, Department of Horticultural NYSAES, Cornell University, Geneva, NY  14456; Phone: 315-787-2216; Email: tnb1@cornell.edu; Klaas and Mary-Howell Martens, Lakeview Organic Grain, 119 Hamilton Place; Penn Yan, NY  14529
Phone: (315) 531-1038; Email: kandmhfarm@sprintmail.com

Organic Farming System Nutrient Budgets: A Tool for Soil Fertility Management

The long-term goal of this research is to develop tools that can be used by farmers to construct nutrient budgets for nitrogen, phosphorus and potassium in organic cash grain and vegetable production systems. An assessment of the quantity of nutrients entering, leaving and remaining on a farm is the starting point for understanding nutrient cycling. When these flows are documented for the entire rotation cycle, the resulting net balances can be used as a tool to help with soil management decisions and in the interpretation of soil tests. The first step in refining soil fertility management strategies in organic production systems involved interviewing farmers to document their soil fertility management practices and sampling of soil amendments and vegetable and grain crops at harvest for nutrient analysis, to assess the quantities of nutrients entering and leaving the farm. A series of databases were developed that can be used support nutrient management decisions. We also developed a prototype nutrient budgeting tool which would utilize these databases to construct multi-year budgets at the field and farm scale. This prototype budgeting tool currently exists in Excel spreadsheet format and is provided in electronic form. The sample budgets that we have developed for our study sites suggest that the majority of organic vegetable production systems are adding significant surpluses of the major nutrients, as much as 180-200 kg P and N ha yr in excess. While these surpluses have been -1 -1 viewed as necessary during the transition to organic management, they will clearly lead to environmental problems if they are continued on a long-term basis. We have also found a number of both grain and vegetable farms are achieving profitable yields without large surpluses of P and N supporting the idea that organic systems have the potential to operate with very high nutrient use efficiency. Additional funding for this effort was received from the Organic Farming Research Foundation

**Laurie E. Drinkwater, Associate Professor, Department of Horticulture, Cornell University

Ithaca , NY 14853 ; Tel: 607 255-9408; Email: led24@cornell.edu

Microbial Seed Treatments for Organic Field Corn

In an effort to promote more consistent and higher stand counts and crop vigor in organic field corn, we tested the effectiveness of four commercial microbial seed inoculants and one compost inoculant on stand, early vigor, and yield of corn crops on organic field crop farms in the Finger Lakes region of New York . Funding was received from the Organic Farming Research Foundation for this work. A trial was conducted on four organically managed fields planted to field corn in 2004, in which four microbial inoculants (Kodiak, Yieldshield, T-22 Planter Box, and Mycostop Mix), and one sieved dairy manure compost were applied to corn seed prior to planting. No significant differences were found among treatments and a control treatment having no inoculant applied to seed. Stand and corn yield in all treatments were good. In 2004, soil temperatures at the time of planting the trial were adequate for rapid germination and growth of corn, so that the establishing corn crop may not have faced any limitation from soil pathogens that these biofungicidal treatments were intended to alleviate. In previous years when stand was poor in some organic corn fields, records of air temperature show that soil temperatures were likely lower, which would have favored seed and root rot pathogens relative to germinating corn seedlings. More challenging conditions to early corn growth may be required in future trials to demonstrate the utility of microbial or compost inoculants for seed in an on-farm setting. This project was a collaboration with farmers John Myer and Klaas and Mary-Howell Martens

**Steve Vanek, Department of Horticulture, Cornell University, 161 Plant Science, Ithaca, NY 14853; Phone: 607 254-2945; Email: sjv2@cornell.edu. **Anu Rangarajan, Associate Professor, Dept. of Horticulture.

Organic Food Grade Soybeans

Food grade soybeans have been included in a study comparing two 5-year organic rotations at the Cornell Willsboro Research Farm. They were included for several reasons: soybeans fix nitrogen and contribute nitrogen to the system, soybeans help break up pest and disease cycles that can build up in rotations that include several grass family members, and the increased interest in the human nutritional qualities of soy has increased demand for organically grown food grade soybeans.

In 2001 eight food grade varieties were obtained from Prograin Inc. (a Quebec company) and a replicated trial was designed to (1) evaluate the performance of regionally adapted varieties in an organic production system, and (2) determine the influence of row spacing on yield and the effectiveness of organic weed control measures.

Weed control strategies included a late summer fallow period to kill the sod and reduce perennial weed pressure, a stale seedbed in the spring to control early season annuals, and a blind cultivation with a rotary hoe when plants were 3-4” tall. Plots with 30” row spacings sometimes received an additional cultivation with sweeps between the rows. Weed control was excellent in all plots.

Yields varied significantly with variety and mean yields ranged from 33 to 61 bu/acre. Varieties that were selected for particular quality characteristics, such as high protein content, had relatively low yields, indicating that a trade-off exists between quality and yield. The 7” row spacing plots generally had higher yields than the 30” row spacing plots.

The initial trial was conducted in 2001 and 2002. Seven new food grade soybean varieties were included in the 2003 trial.

**Michael H. Davis, Farm Manager, Cornell Willsboro Research Farm, Farrell Road , Willsboro NY , 12996 ; Phone: 518-963-7492; Email: mhd11@cornell.edu