Congratulations to Lauren Schwarck for successfully defending her Masters Thesis:
Towards Optimization of Alternate-Source Potassium Applications in Conservation Tillage Systems for Maize Production: A Mechanistic Approach
Few investigations into the optimization of potassium (K) management in conservation tillage systems have addressed K-based fertilizer placement method and/or timing for maize production in the Eastern Cornbelt. Because the exchangeable K stratification from low soil disturbance is thought to potentially limit K availability to maize, K fertilizer management should be reevaluated. The tillage treatments of no till [NT], fall strip-till [FST], spring strip-till [SST], and fall chisel [FC]), each with their own unique fertilizer placement, were compared with at least two application rates of Aspire™ (ranging from 0 to 108 kg K ha-1) from 2016 to 2019 on Indiana soils with moderate exchangeable K concentrations. Although tillage systems, other than no-till, were intended to decrease K stratification, little change in vertical stratification for in-row samples was observed in the strip-till systems when Aspire™ was band applied at the time of strip-till (indicating fertilizer application in the coulter-based strip-till systems was limited to near-surface soil). Few interactions were evident in maize response between tillage systems and Aspire™ applications; however, superior V6-stage growth/nutrition responses to Aspire™ application occurred in fall tillage systems (FST or FC). The latter was especially true when comparing the two strip-till timings (FST and SST) at three rates. In addition to early season plant nutritional benefits, plant stature also benefited from Aspire™ across tillage systems (e.g. ~20% increase in height at V8, plus a leaf area index gain at V14 of ~10%) reflecting a potential to increase maize plant source capacity. By R1, there was little treatment interaction in plant parameters, few differences among the tillage system (and strip-till timing) responses with Aspire™, and few immediate consequences from a 50% rate reduction for Aspire™ in either strip-till system. Although grain yield increases of 4-8% were common when Aspire™ was applied, yield component analysis showed little interaction between tillage systems and Aspire™. Grain yields were more correlated to R1 earleaf K concentration, and less so with minor changes in earleaf B concentrations. Aspire™ application at the full and 50% rate commonly benefited total plant nutrient uptake (at times numerically for B and significantly for K as well as P) and grain yield, but little interaction between Aspire rate and tillage systems was evident. Although rate reduction did not show immediate consequences to plant nutrition in either strip-till timing, longer-term research is necessary to better understand future consequences from this management approach. This research confirmed the importance of K fertilization to maize performance, but the efficient management of K requires further inquiry.
Welcome to Vyn Labs!
Here we share who we are, what we've been learning, and the latest updates on our research.
The primary mission of the Cropping Systems Lab is to critically evaluate potentially sustainable agricultural technologies for field crop production from the relevant perspectives of genotype by environment by management system interactions that farmers encounter. In pursuit of that overall mission, our research group endeavors to use our talents and resources to
(a) advance the scientific understanding of plant response mechanisms to specific crop inputs,
(b) enhance the sustainability of crop production practices in the Eastern Corn Belt,
(c) train great students who can contribute to the future growth of even more sustainable crop production practices.