Post emergence land rolling influences soybean plant architecture but not yield

Abstract

<p>Increasing the number of nodes for subsequent pod development by soybean [Glycine max (L.) Merr.] may be an approach to improve yield. Land rolling is a common practice in soybean production to push rocks and corn (Zea mays L.) root balls back to the soil surface to protect combine harvesters. Limited research has been done to determine if land rolling can change plant architecture by breaking apical dominance of soybean to induce lateral branching and provide greater node and pod numbers. The objective of this experiment was to determine if land rolling soybeans could break apical dominance to induce lateral branching, increase reproductive node number, and improve yield. Field experiments were conducted in 2017 and 2018 using a randomized complete block design with five replications. Treatments consisted of a control that was not rolled, rolling pre-emergence, and rolling at the V2, V3 and V4 stages of development. Collected data included counts of main stems and branches, nodes on main stems, and branches that did or did not have pods, pod numbers on main stems and branches, stand density, and grain yield. Land rolling decreased main stem numbers, and reproductive nodes and pods on main stems. Land rolling soybean post emergence consistently decreased stand density in 2018 but only decreased stand on one of three post emergence timings in 2017. However, land rolling did not influence branch numbers or branch nodes and pods. Land rolling influenced soybean plant architecture but did not influence yield when done pre-emergence or post-emergence.</p>