Harvest time is denoted by the rustle of dried leaves, smell of dust, pink beeswings tumbling through the air and bright tractor cab lights illuminating clear nights. But how do farmers know when it’s time to break out the combines and grain carts and start this busy and fruitful time of year? It’s all a function of maturity and weather.
When a farmer goes to harvest corn, he or she has a few considerations. A farmer knows that the corn is ready when the plant stops filling the kernel with starch, and the tip of the kernel is closed off from the cob. This can be seen when the tip is broken off the kernel, and is called the black layer. At this time, the corn is dead and continues to dry in the field.
Once corn has reached the black layer stage, the moisture of the kernels becomes a determining factor. The moisture is affected by factors like temperature, rainfall, and humidity. Farmers can test the moisture of the corn by running it though a moisture tester. The average kernel at black layer will be 30% moisture. Corn can be harvested at 30% moisture but not be stored unless it is around 15% moisture. Farmers may choose to harvest wetter corn at 20%-30% moisture and use a grain dryer to dry the corn down to an acceptable storage moisture level. Some farmers may choose to wait for the corn to dry down in the fields, but this takes valuable time.
If corn is harvested too early, the farmer must pay for the drying costs to lower the moisture. The stalks can also be tough and hard for the combine to harvest. If corn is harvested too late, the ears may fall off the plant or the stalks may fall over, making it more difficult to combine them. Waiting too long to harvest corn incurs more loss of grain in the field.
Soybeans must be harvested at the right moisture, just like corn, but it’s tougher to get them to the right moisture. Soybeans absorb water from morning dew and rain, which can raise the moisture percent, but wind, heat and sunshine can lower that moisture in a matter of hours. Farmers have to wait for soybeans to dry down from the dew each day before harvesting.
Farmers get lower prices when they sell their grain if the soybeans are over 13% moisture. Soybeans are sold by weight, and if the soybeans are less than 13% moisture, a farmer won’t get paid as much for the weight of the soybean. Farmers most often test for the moisture of their beans in a very scientific and accurate way – they will bite the beans. If the beans snap, they are close to the right moisture for harvest. If they don’t they need to dry down more.
Waiting too long to harvest soybeans can lead to lower yields because the pods become brittle and split open. If beans are harvested too early, they are difficult for the combine to harvest and spoil quickly.
Like all things in agriculture, harvest time is a balancing act between time and weather. Each farmer looks at the risks associated with harvest differently, and may decide when to start harvest accordingly. The farming year is a success when the crop is out of the field and in the bins, and there’s nothing a farmer loves more than seeing the product of their labor come to fruition.