Last November, Dr. Manbir Rakkar (Assistant Professor of Soil Fertility and Nutrient Management) and Jaspreet Singh (Master’s student in Dr. Rakkar’s lab) attended the 54th Annual North Central Extension – Industry Soil Fertility Conference in Des Moines, Iowa.
This meeting welcomed attendees with presentations ranging from soil test based to return on investment based nutrient management , among other interesting topics.
Dr. Manbir Rakkar presented: “Crop and Soil Response to Different Phosphorus Management Approaches”, in which she explained how the study will help to refine phosphorous fertilizer recommendations in Ohio. In the study, soil and plant data were collected from three Phosphorus (P) fertilizer trials (Wooster, South Charleston, and Custar), established in 2006. These sites have three fertilizer approaches: no P, maintenance, and build up, replicated four times within a corn-soybean rotation. The preliminary data showed that soil P levels were different across the approaches with the no P approach containing the lowest soil P levels. Despite different soil P levels, there was infrequent yield response during the study period. Future research will focus on understanding the relationship between soil P levels, P approaches, and P uptake in both crop and grain, as well as correlating soil properties such as pH and organic matter to better understand P budgets across Ohio.
Jaspreet Singh presented: “Impact of Different Inorganic Phosphorus (P) Fertilizer Rates on Soil P Pools” where he explained how data from Ohio fertilizer trials (Wooster, South Charleston, and Custar) show that the application of P can lead to an accumulation in the available pool, but crop yield responses remain unaffected. In this study,all sites received fertilizer applications since 2006 and have been in a drawdown phase (no fertilizer application) since 2021. Preliminary data collected in the summer of 2024 indicated that P saturation levels were highest when P was applied with a build-up approach (9.12%) followed by maintenance approach(7.09%) and no P application (5.67%) across sites. The relationships between P saturation and water-extractable P (P-solubility) will be examined to illustrate how soil P solubility changes as soil P saturation increases in this study. The results of this study will highlight the impact of fertilizer rates on soil P pools which could potentially effect crop production and water quality.
Authors: Aline de Camargo Santos, Valeria Moreira, Naiima Abdi, and Manbir Rakkar.