Document Type
Thesis - Open Access
Award Date
2025
Degree Name
Master of Science (MS)
Department / School
Agronomy, Horticulture, and Plant Science
First Advisor
Peter Kovacs
Abstract
In South Dakota, the adoption of no-till and other conservation tillage practices has grown in recent years. However, conventional tillage is still a common practice in the eastern third of the state, negatively affecting soil health and the environment. Strip-tillage has gained interest in this region as a way to transition to conservation tillage while retaining some benefits of conventional tillage. Strip-tillage also provides the ability to subsurface band nutrients, particularly phosphorus (P) and potassium (K) fertilizers within the tillage strip, potentially improving nutrient accessibility and recovery while reducing environmental risks. This study aimed to investigate (i) the effects of fall and spring strip-tillage timing on corn development and grain yield, and (ii) the impacts of P and K fertilizer placement and timing with strip-tillage banding, broadcasting, and starter fertilizer placement on crop development, nutrient uptake, and grain yield. Field experiments were conducted at Brookings, SD (BRS) and South Shore, SD (NERF) in 2024, comparing fall conventional tillage with broadcast fertilizer (FCT BR), fall strip-till with broadcast fertilizer (FST BR), fall strip-till with banded fertilizer (FST BA), spring strip-till with broadcast fertilizer (SST BR), and spring strip-till with banded fertilizer (SST BA). A fall no-till broadcast fertilizer (FNT BR) treatment was also used at the NERF site. Fertilizer additions of a PK fertilizer mix were made at three rates: the university recommended rate (309 kg ha-1 PK mix; supplying 82 kg ha-1 P2O5 and 60 kg ha-1 K2O), a reduced rate (224 kg ha-1 PK mix; supplying 60 kg ha-1 P2O5 and 43 kg ha-1 K2O), and a control (0 kg ha-1). Additionally, starter fertilizer (10-34-0) treatments were banded with 5x5 cm placement at 47 L ha-1 or 0 L ha-1 rates. Tillage/fertilizer placement and timing combinations saw response differences at each site. At BRS, FCT BR yielded the highest with 13.6 Mg ha-1. SST BA yielded 0.6 Mg ha-1 less, while FST BA had statistically similar yields to both treatments. FST saw grain yields 0.6 Mg ha-1 greater than SST for broadcasted fertilizer placement, while lagging behind FCT BR by 0.4 Mg ha-1. At NERF, SST BA yielded the highest with 13.4 Mg ha-1, while being statistically similar to FCT BR. FST BA yields were similar to FNT BR and lagged behind both SST BA and FCT BR by 0.5 Mg ha-1 and 0.4 Mg ha-1, respectively. FST and SST experienced similar grain yield to each other and FCT BR with broadcast placement, while still outyielding FNT BR. Banded and broadcasted placements saw no significant yield differences within the same strip-tillage timing at both sites. The yield results at both sites closely align with many of the measurements collected throughout the growing season. At both sites, fertilizer responses were observed from 0 to 224 kg ha-1 rates, with positive responses at BRS and negative responses at NERF with the use of P and K fertilizer. However, the lack of responses from 224 to 309 kg ha-1 fertilizer rates at both sites prevented a determination if fertilizer rates could be reduced with strip-tillage banded placement. While starter fertilizer use was observed to improve early growth and nutrient uptake across treatments at both sites, no trend was observed indicating an interaction between starter fertilizer use and strip-tillage banded fertilizer placement. Therefore, these results indicate that while strip-tillage can sometimes provide comparable crop development and grain yield as conventional tillage, reductions in growth and yield can still be experienced based on site-specific factors. These results also showed little difference between banded and broadcasted placements and fertilizer rates, highlighting potential for further research on more responsive sites.
Publisher
South Dakota State University
Recommended Citation
Tesch, Charles N., "Evaluation of Strip-Tillage and Banded Phosphorus and Potassium Fertilizer for Corn Production in Eastern South Dakota" (2025). Electronic Theses and Dissertations. 1542.
https://openprairie.sdstate.edu/etd2/1542
Rights Statement
