Nitrogen Mineralization and Yield Components in Organic Rice in Relation to Soil Amendment.

Since 1995, organic rice acreage has increased almost six fold with up to half of the acreage being grown in the southern US. The industry has expanded rapidly (up to 20,000 ha/year), failing to meet market demand resulting in increasing pressure from foreign organic rice imports. In addition, because of the unique flooded rice paddy production system used throughout the US, there is little information from other organic cereal grains cropping systems that is applicable to rice. Previous informal surveys of industry representatives helped identify critical issues related to organic rice production including nutrient management, weed control, and rice cultivars with high economic returns. The restricted availability of nutrients, particularly nitrogen (N), is one of the primary reasons for low yields in organic farming. To determine the effect of soil amendment on organic rice production, a greenhouse trial in Beaumont, TX, was conducted from May to August 2015. The effects of organic soil amendment (Nature Safe) with six different rates of application (0, 50, 100, 200, and 250 kg N/ha) on soil inorganic N and rice production were studied.