Corn and soybean harvest timing and efficiency

Harvest Timing and Efficiency: Key Factors for Crop Growers

Harvest is the culmination of all of your agronomic choices as influenced by the vagaries of weather. When the grain is mature, it presents the maximum return from your efforts but is still in the field and needs to be harvested. Harvest timing and efficiency will determine how much grain you get to the bin or elevator. There are several important factors to consider in the "when and how" of your harvest operations, particularly on larger farms with a variety of corn and soybean maturity groups in the field.

📸: BASF Contributing Writer/Featuring the harvest well underway with a combine downloading into a grain cart.

Soybean Harvest Efficiency: Starts at the Combine Head

Soybean harvest efficiency is largely determined at the combine head and cutter bar. Mismatched maturity groups and open canopies can result in very low pods that are below the level of the grain table. Misaligned combine ground speed and cutter bar speed may allow soybeans to fall to the ground. The greatest risk for pod shatter is when dry pods ready for harvest receive rain, rehydrate, then dry, and split.

📸: BASF Contributing Writer/Featuring Soybean Harvest Loss: leaving low pods unharvested (Left) or combining issues (Right)

Corn Ear Drop: Causes and Prevention

Ear drop is an obvious loss pathway for harvested corn. Great improvements have been made over recent years as the adoption of Bt corn and increased use of fungicides have kept more ears on the corn stalk where they can be successfully harvested. Despite these agronomic advances, some environmental conditions can still lead to "ear drop". Among those would be conditions where a weak shank develops due to moisture stress at silking and then a very heavy ear develops due to excellent nutrition and soil moisture during grain fill. A big, heavy ear with a weak, brittle shank sets up conditions for ear drop, especially if the shank attachment becomes further weakened by rapid dry-down after maturity.

Stalk Rot Diseases: A Threat to Harvest Efficiency

Stalk rot diseases are still an important factor affecting stalk integrity and the ability of that stalk to hold the ear until harvest. Scouting to evaluate stalk integrity is an excellent approach to correctly ordering the field harvest sequence. Fields with weak stalks, lodging, and disease are important factors to consider, as well as maturity and in-field grain moisture content. Several manual techniques exist to get a relative measure of stalk integrity. Poor N, or K nutrition as well as stalk disease can result in weak stalks. Squeezing a stalk at the 2nd or 3rd internode will give you an idea of its strength. Pulling into a field and combining a short run before the combine spews out stalks and other residue will provide an opportunity to count or observe grain that has come through the combine. One dropped ear of corn per 100 feet, or 25 kernels/10 ft,² is equal to 1-1.5 bushels per acre loss. Forty soybeans on the ground for 10 ft² is also equal to 1–1.5 bushels.

📸: BASF Contributing Writer/Featuring corn harvest loss with dropped ears due to weak stalks (Left) or combine settings (Right)

📸: BASF Contributing Writer/Featuring an early harvest (Left) followed by tillage, which might reveal losses through the combine (Right), allowing the grain to germinate and emerge.

Combine Settings, Speed, and Operation for Efficient Harvest

Combine settings, speed, and operation can all be important factors leading to a more efficient harvest. Combine adjustments are complex and include evaluation within the combining process as grain and chaff are separated. As mentioned, an evaluation is best made by pulling into the field and combining a short strip, stopping prior to the discharge of the stover, thus allowing a better observation of how much grain is on the ground.

Harvesting in Sequence to Minimize Losses

Consider harvesting your fields in sequence to be the most vulnerable to ear drop or soybean pod shattering, paying special attention to grain moisture, which will affect both harvest efficiency and profit at the point of sale.

Coming next: Are cover crops for you?

BASF provides the information in this article as a service to its customers; however, the views expressed by guest writers are their own and do not necessarily reflect the views of BASF.