No Till Notes: 'Conservation agriculture, part 2'

Last week I introduced you to Rattan Lal, director of the Carbon Management and Sequestration Center at Ohio State University.

Lal published an article on his concepts for developing a conservation agricultural system for our farms and ranches. His concepts involve adapting five steps towards a complex conservation agricultural system which concentrates on improving the soil’s health as we move into the future of production agriculture across our nation. Last week we looked at the first three steps in adopting this system.

The first of these steps is to adopt no-till crop production practices with minimal soil disturbance. Step two is to leave the previous crops residues attached and on the soil’s surface. Step three is the introduction of diverse cover crops or forage crops into your conservation agricultural system.

Lal sees the fourth step in adopting a conservation agricultural system as adoption of a complex crop rotation. Ideally this complex crop rotation will include all four crop types of warm and cool season grasses and broadleaf plants within the rotation. Adopting a diverse cropping rotation has many benefits. These benefits include the breaking up of persistent weed and disease cycles. Diverse crop rotations allows for use of diverse herbicides applied at different times during the growing season which helps combat persistent weed cycles. Beck has said that if you have a persistent weed problem on your farm it is because you have created the opportunity for that weed species to thrive.

Disease cycles can also be broken by diverse crop rotations. By mixing grass and broadleaf crops within the rotation many diseases will lose their opportunity to establish themselves. I would also include insect cycles being broken with diverse cropping rotations. Many insects will remain below threshold levels of crop damage if their growing cycles are broken with diverse crop rotations.

Cover crops and forage crops are a good way to add diversity into your cropping rotation if the cash crops you grow don’t cover all four crop types. An example would be if you have a crop rotation of winter wheat, a cool season grass, forages for grazing and field peas, a cool season broadleaf. During the forage portion of the rotation warm season grasses and broadleaves could be utilized as forages to complete all four crop types.

The adoption of complex crop rotations will also increase the populations and diversity of soil microbes in your soil. Different microbes thrive under different crop rotations. If you have a balance of crop types growing on your farm, your soil will develop a balance of soil microbes.

Lal includes integrated nutrient management as his final step towards a complete conservation agricultural system. Applying fertilizers at different times during the crop’s growing season will help improve water quality by avoiding runoff or leaching of commercial fertilizers.

On our farm we have adopted integrated nutrient management by applying fertilizers in smaller quantities more often during the crop’s growing cycle. In the past we tended to apply the majority of our fertilizers prior to planting. We now utilize our center pivots on our irrigated acres to apply nutrients throughout the growing season on our corn, winter wheat, and dry edible bean acres. We also apply starter fertilizers at planting.

On our dry land acres we now use our sprayer equipped with streamer bar nozzles to apply fertilizers on our dry land winter wheat and corn during split applications of our fertilizers along with starter fertilizers applied at seeding. Adopting these split fertilizer applications allows us to minimize any opportunities for fertilizer to runoff or leach in our fields.

I would encourage you to adopt Lal’s concepts to a complex conservation agricultural system on your farm or ranch. I would be happy to forward these articles written by him if you send me an e-mail request to [email protected].