2011 Rice Season Off to a Good Start

Barrett A. Courville  |  4/5/2011 7:38:31 PM

The start of the 2011 rice growing season is getting off to a terrific start. The weather has been perfect for planting and getting the rice to start growing. I can’t remember a year where we have had this much rice planted this early in the growing season. I am estimating that by April 1, 2011, we will have 80 percent or more of the rice planted. Research has shown that the best yields are always on rice that is planted early before April 15. This will also be beneficial for the producers who will want to second crop this year. Generally, rice planted before April 15 will be able to produce a second crop before the weather turns cool in the fall.

I wanted to give a refresher course on fertilizer recommendations. Most producers will be applying fertilizer shortly. Phosphorus and potassium should be applied according to soil test recommendations. On soils where phospho­rus and potassium are needed, apply preplant or before first flood. Potassium deficiency has been associated with increased disease incidence and severity.

Fertilizer nutrients are most efficiently used by rice when applied immediately before permanent flood establishment. There are situations when fall application of some nutrients may be a suitable alternative. Neither nitrogen nor zinc, however, should be applied in the fall.

Rice seedlings usually show nitrogen deficiency within 15-25 days after seeding, especially in soils low in organic matter. A preplant application of 15-30 pounds of nitrogen per acre is usually needed to meet the seedling nitrogen requirement before permanent flood. All or most of the nitrogen can be applied preplant in a water-seeded pinpoint flood system. In a drill-seeded, dry broadcast or water-seeded delayed flood system, all or part of the nitrogen may be applied immediately before permanent flood. The balance of the nitrogen can be ap­plied when deficiency symptoms occur or anytime up to the panicle differentiation (2 mm panicle) growth stage. Avoid applying nitrogen-containing fertilizers more than seven days before planting.

Nitrogen fertilizer applied as urea is prone to loss through ammonia volatilization. Agrotain is a urease in­hibitor that delays breakdown of urea, minimizing nitrogen loss associated with ammonia volatilization. Agrotain will improve nitrogen efficiency when urea is applied on a wet soil surface before permanent flood or when urea is ap­plied to soil surface more than three to five days before permanent flood. Results may vary with year and/or environment.

Rice varieties may differ in their nitrogen require­ments by location. Native soil fertility, soil type and other factors determine the efficiency of nitrogen utilization. Rice growers should determine the N rate that provides optimum grain yield on their land. The higher nitrogen rates within the recommended ranges for each variety are generally required in central and northeast Louisiana. Avoid N deficiency and excessive N fertilization.

Varieties vary in their nitrogen needs. These recommendations are based on multiyear, multiloca­tion research throughout Louisiana. These rates assume proper timing.

Ratoon, or second-crop rice, should be fertilized with 75-90 pounds of nitrogen per acre when first crop harvest is before August 15. When first-crop is harvested after August 15, fertilize with 30-45 pounds of nitrogen per acre. When conditions appear favorable for good second crop production (minimal field rutting, little or no red rice, healthy stubble), apply the higher rate of nitrogen. Apply nitrogen and establish a shallow flood within five days after harvest. Research has consistently shown that nitrogen fertilizer should be applied and the field flooded as soon as possible after first crop harvest to maximize second crop yields. When the main crop is harvested after August 15, the potential for profitable second crop production is reduced because of the probable delay in maturity especially at higher nitrogen rates and the in­creased likelihood of unfavorable weather.

On soil with a history of zinc deficiency, or where soil tests indicate a need for zinc, a soil application of 10 pounds of zinc from an inorganic source (zinc sulfate) or 1-2 pounds of zinc per acre as a chelate should be made. Zinc can be applied foliarly at the rate of 0.5-1.0 pound per acre as a chelate.

Sulfur may be needed at a rate of 20-25 pounds per acre where large amounts of soil have been moved in land leveling. Sulfur deficiencies resemble nitrogen deficiencies, producing pale yellow plants which grow slowly. If these symptoms appear, applying 100 pounds of ammonium sulfate per acre will provide 21 pounds of nitrogen and 24 pounds of sulfur per acre.

Nitrogen Recommendations for Rice Varieties

Varieties

N rate (lbs/A)

Bengal, Catahoula, Cheniere CL131, CL142, CL161, CL162, CL181, CL261, Cocodrie, Cypress, Jazzman, Neptune, Taggart, Templeton, Wells

120-160

CL151

90 - 130

Della

70 - 100

 


For more information call or come by your parish office.

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