- Agronomic: canola
- Crop Production: fertilizers, nutrient management
- Education and Training: extension, on-farm/ranch research
Winter wheat production in Texas has been in decline in recent years due to fluctuations in the agricultural commodity market. Incorporation of canola as a rotational crop in cropping systems involving wheat would diversify the farm operation, enhance crop sustainability by shortening the fallow periods, rotate herbicide chemistry, and break disease and pest cycles of wheat. Field research in canola indicates the crop has adaptability to the growing conditions in Central Texas, where grain yields above 2,000 lb ac-1 can be attained. However, further agronomic research on canola is required for the identification and adoption of the best management practices for this crop. A critical aspect for the success of canola production in Texas relates to rapid plant establishment. Furrow application of monoammonium phosphate (MAP) and diammonium phosphate (DAP) have proven to positively contribute to early growth and good stand establishment. The objective of this on-farm research study was to determine best in-furrow rates for starter MAP and DAP fertilizer that maximize economic returns for canola in a representative site of the Blacklands region.
A field study was implemented near Perry in Central Texas in which spring canola ‘CP9978F’was evaluated under the furrow application, at planting, of 14 fertilizer treatments plus one control arranged in a randomized complete block design with four replications. Fertilizer treatments consisted of different rates of MAP and DAP fertilizers with and without the addition of ZnSO4.
A cold front that went across Texas in early February 2020 affected the crop by delaying its early growth, and excess soil moisture during maturity significantly and negatively impacted yield performance and grain quality. Although no response in grain yield to the fertilizer application was observed, freeze damage, maturity, and test weight showed significant variation. Freeze damage was accentuated under treatments 136 MAP, 91 MAP, 45 MAP, and 28 DAP. It is inferred this was the result of an increased vegetative tissue under these treatments which were exposed to freezing temperatures. Control plants and those under ZnSO4 treatment matured early and yielded relatively low, suggesting these conditions provided inadequate soil nutrients available for proper development of the crop. The crop under the MAP fertilizer treatments tended to mature relatively late but also yielded low, which was probably the result of a reduced phosphorus mobilization in the soil after the initial stages of growth, the freeze damage observed during early growth and the excess soil moisture during the grain filling stage, which in turn caused lodging and seed shatter, or by a combination of all.
Freeze damage during early growth and excessive moisture during the late phase of crop development had a detrimental influence on the response of canola to the application of band fertilizer in this study, causing a confounding effect driven by changes in plant density and delayed crop maturity.
This project aims to increase sustainability by promoting the adoption of canola, a potential rotational crop for the Blacklands Region of Texas, which if successful would shorten fallow periods in wheat rotations, and improve weed control through better chemical rotation. By focusing on fertility, this study will determine best in-furrow rates for starter fertilizer that maximize economic returns for canola, and reduce residual nutrients in the soil, lowering risk of off-site movement into waterways.