Planting depth study in Maize
Study Contact: Benard Ngwene, AGCO Agronomist, Africa.
Benard.ngwene@agcocorp.com
OBJECTIVE:
The objective of the study was to demonstrate the effect of planting depth on maize grain yield
STUDY DESIGN:
During the 2018/2019 cropping season, maize yield was compared at different planting depths (2.5, 4, 7, and 9 cm) using the MF 9812 precision planter at the AGCO future farm in Zambia.
RESULTS:
Overall grain yield was lower than average due to very low precipitation in this region during the 2018/2019 cropping season. Planting at 7 cm deep resulted in the overall highest yield (6.2 tons/ha) (Figure 1). Comparable yields (about 7% lower) were obtained at the 4 and 9 cm planting depths, whereas planting at 2.5 cm deep resulted in the lowest yield (about 10% lover).
Adequate soil moisture is critical for rapid and uniform seed germination, along with root establishment. Therefore, farmers should always aim to plant seeds where moisture is present. In this trial, according to the yield results, 7 cm was the optimal planting depth. Although there was also adequate moisture at 9 cm deep, the seedlings require more energy to reach the surface.
AGCO RESEARCH SUMMARY | 01

Figure 1. Maize yield in tons/ha dry matter at harvest. Maize was planted at 2.5, 4.0, 7.0, and 9.0 cm planting depth and harvested at maturity
ADDITIONAL OBSERVATIONS:
Planting at 7 cm ensured more even emergence and better use of plant resources.
RECOMMENDATIONS AND EQUIPMENT SOLUTIONS:
Considering the importance of soil moisture for seed germination, it is recommended to check moisture levels before and during planting and adjust planting depth accordingly. SmartFirmer™ soil sensor measures soil moisture in real time during planting.
PAYBACK:
There was an average 0.5t/ha reduction in maize yield from a wrong planting depth as compared to the best yield. This equates to an average increase revenue of $70/ha.
Assumptions:
Average price of maize – $140/t
AGCO RESEARCH SUMMARY | 02
Figure 1: Wheat yield in tons/ha dry matter at harvest. Wheat was planted with a wheat drill in a ripped field and in an untilled field.
Figure 2: Wheat seeded directly – no-till
Figure 3:
Wheat seeded on a ripped field. (There are less soil disturbance and more soil
cover in the no-till field.)