Showing posts from December, 2022

Avoiding Herbicide Carryover

  With a new year coming, farmers are buying inputs for next years crops. Now is the time to think about purchasing herbicides, but also think about how to avoid herbicide carryover, especially if planting cover crops. Factors that increase herbicide carryover include dry weather, late application especially on herbicides with long half-lives, low soil microbial activity, low soil organic matter (SOM), and cooler and cloudy days. Soil texture (especially sandy soils with low SOM) and soil pH also affect herbicide breakdown. In soybeans, there are five major types of herbicides to watch to avoid herbicide carryover. Flexistar/Reflex and Warrant Ultra (fomesafen) soybean herbicides have a long half-life with up to 18 months planting restriction for small seeded legumes and clovers, brassicas (radish, kale, rape), and even some grasses (oats 4-18 months, rye, wheat, barley 4-11 months). The mode of action is a Group 14 which is a PPO inhibitor (causes reactive oxygen). Authority, Optill,

Planting Small Seeded Clovers and Legumes

Planting small seeded clovers and legumes can be challenging, be that for forages or as a cover crop. Soil types, surface residue, weather especially moisture, seeding depth and getting the right rate on can all either cause a failure or a reduced stand. Here are a couple planting tips. Small seeded clovers and legumes can grow well in sandy loam soils to clay soils with some modifications. Sandy soils tend to dry out and the seed may move too deep in the soil at planting. On clay soils, the soil may be more compacted but they tend to hold more moisture. If the seed stays to close to the surface, without adequate rain, the seed may dry out or get tied up in a thick crust. Often a nurse crop (oats) may help small seeded crops emerge and also initiate critical microbes that can assist a small seedling in germination and growth. Most clovers and legumes need a good pH and lime (calcium carbonate) or gypsum (calcium sulfate) to have good germination. Adequate calcium is needed to initiate

Cover Crop or Cash Crop?

  Cover crops protect the soil, build organic matter, and promote healthy soils. Some cover crops are used as forages (sorghum, triticale, and clovers) while others are used for grain (barley, milo, oats, wheat, rye). Now a winter cover crop (winter pea) has been bred for human food and another (penny cress) for oil. Several winter cover crops may now offer farmers additional cash while providing environmental benefits.  USDA-Agricultural Research Service (ARS) has been researching winter or autumn-sown peas (Pisum sativum) also called "black peas" or "field peas” which are annual legumes with excellent nitrogen-fixing abilities. These pea species originated in the eastern Mediterranean and western Asia. They should not be confused with cowpeas (Vigna unguiculata), a summer annual which are also known as field peas. Winter peas have been traditionally grown as a cover crop to generate nitrogen, used as animal feed, or used in wildlife plots. Now winter peas (WP) have bee