Effect of phosphorus placement in reduced tillage crop production
dc.contributor.author | Martin, Kent Lee | |
dc.date.accessioned | 2009-01-20T18:50:37Z | |
dc.date.available | 2009-01-20T18:50:37Z | |
dc.date.graduationmonth | May | en |
dc.date.issued | 2009-01-20T18:50:37Z | |
dc.date.published | 2009 | en |
dc.description.abstract | A number of questions are being raised concerning phosphorus (P) management as producers switch to minimum or no-tillage cropping systems. Benefits of P application are site specific and potential advantages need to be evaluated for each location. Deep band application effects on crop yield and soil P distribution have been studied, but conclusive results are lacking because of the complexity of environment and P placement interactions, particularly in moisture limited environments. Challenges in soil test sampling and interpretation have also affected P management in these reduced and no-tillage systems because of decreased confidence in soil test P data. The objectives of this research were to evaluate crop responses to P application rate and placement and to study the distribution of soil P concentration, both vertically and laterally at a number of locations in Kansas. This research shows that crop growth at the sites evaluated was not negatively affected by P stratification, which was present at all sites at the beginning of the study. Phosphorus placement methods (broadcast and deep band) did not have significant effects on P responses. However, P application was required to achieve maximum yields at sites with low soil P, but high P sites did not consistently respond to P application. When P fertilizer was broadcast, shallow soil depths continued to have high soil test P, while deep band application increased soil P in the 7.6 to 15 cm depth. The addition of starter application with deep banding of P generally resulted in a more even vertical distribution of soil P. Soil test P data also demonstrated that the presence of bands can be confirmed through soil sampling, but the confidence of soil test P data in a vertical and lateral stratified soil was decreased. Soil samples taken from the band area had highly variable P (high coefficient of variation) concentrations likely due to an inability to sample from within the P band or variability in P application. Soil sampling in these management systems proves to be challenging and will need further research to identify improved methods for soil test P sampling and interpretation. | en |
dc.description.advisor | David B. Mengel | en |
dc.description.degree | Doctor of Philosophy | en |
dc.description.department | Department of Agronomy | en |
dc.description.level | Doctoral | en |
dc.description.sponsorship | International Plant Nutrition Institute, Agrium, Mosaic, Potash Corp, Simplot | en |
dc.identifier.uri | http://hdl.handle.net/2097/1223 | |
dc.language.iso | en_US | en |
dc.publisher | Kansas State University | en |
dc.subject | phosphorus | en |
dc.subject | stratification | en |
dc.subject.umi | Agriculture, Agronomy (0285) | en |
dc.title | Effect of phosphorus placement in reduced tillage crop production | en |
dc.type | Dissertation | en |