Effects of Sodium Nitrate on Stand and Yield of Organic Spring Feed Barley in the Klamath Basin.

The Klamath Basin of southern Oregon and northern California produces about 20,000 acres of certified organic crops (primarily small grains, alfalfa hay, and potatoes) on both mineral (low organic matter) and lake bottom (high organic matter) soils. Growers utilize crop rotation, winter flooding, and other soil building practices but organic crops are often N deficient, even on the lake bottom soils having as much as 30% organic matter.  Natural Sodium Nitrate from Chile is the only commercially available nitrate fertilizer that can be used in certified organic crop production.  A maximum of 20% of the total crop N need can be met through the use of sodium nitrate, although that requirement is currently under review.  The objectives of this research were to assess the effects of applying sodium nitrate as a starter fertilizer on the emergence, final stand, crop yield and quality of organic spring feed barley. Sodium nitrate was applied at 0, 18, 36, or 54 kg N ha^-1, either with the seed or banded 2.5 cm below and 2.5 cm beside the seed at planting. The treatments were arranged in a randomized complete block design with four replications at each of two locations, including a lake bottom soil with 6% organic matter (Tulana silt loam), and a mineral soil with less than 1% organic matter (Fordney loamy fine sand). Seedling emergence at 10 days after planting (DAP) was reduced as the N application rate increased, especially when the fertilizer was placed with the seed, on the Fordney soil.  Seedling emergence improved at 20 DAP but treatment differences were still evident.  There were no consistent treatment effects on seedling emergence on the Tulana soil.