| Autor: |
Fromme, Dan D., Hons, Frank, Lemon, Robert G., Robert G. Lemon, Mott, Dale |
| Zdroj: |
Proceedings of the Beltwide Cotton Conferences; 2009, p81-85, 5p, 1 Chart, 1 Graph |
| Abstrakt: |
Previous research in Texas has found widespread incidence of high residual nitrate concentrations in soil profiles in all cotton production regions throughout the state. One reason for the excess nitrate may be over fertilization with nitrogen (N). Currently, Texas AgriLife Extension Service recommends 50 pounds available N/bale of lint. However, these recommendations were based on older conventional varieties. The objective of this study was to determine the nitrogen requirements of commonly used GMO cotton varieties so that fertilization guidelines may be modified to result in more accurate and effective nitrogen recommendations. The study was implemented in San Patricio County, Texas to evaluate four cotton varieties and five nitrogen rate treatments (NRT) under center pivot irrigation. Prior to nitrogen applications, soil samples were taken to depth of four feet to determine residual soil nitrate. Prior to applying the NRT, a total of 54 pounds of residual NO3-N was found to the depth of four feet. For the five NRT, no differences in pounds of lint per acre were found. The 0 NRT produced 1205 pounds of lint per acre on 54 pounds of residual NO3-N. Based our nitrogen recommendations, we had enough residual nitrogen to produce only 540 pounds of lint. Therefore, 66.5 pounds of nitrogen would have to come from mineralization and irrigation water to meet the nitrogen requirements of the additional 665 pounds of lint per acre that was produced. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Supplemental Index |
| Externí odkaz: |
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