No Till notes: 'Water Conservation, Part 3'

Water conservation in irrigated crop production has to be viewed as a systems approach to conserving water.

As I stated in previous articles I think water conservation starts with improving the performance of the soil.

Another key component to a systems approach to water conservation is choosing a dynamic crop rotation for your farm or ranch.

The crops you choose to produce have to be profitable, provide a good agronomic rotation, be relatively high in water use efficiency and require less irrigation for high yields.

On our farm we have chosen an irrigated crop rotation of corn, field peas and winter wheat, followed by a diverse forage crop and edible beans.

We added field peas to our irrigated rotation this past growing season.

I like this rotation for a number of reasons. We now have a rotation which includes all four crop types, warm and cool season grasses and legumes.

This rotation adds a lot of diversity to the rotation which is important. With this rotation we can break up persistent weed and disease cycles and rotate herbicides to lessen herbicide resistance in weeds.

We also have three fairly low water use crops in our system with the winter wheat, edible beans and field peas. The winter wheat and field pea’s water use is also during the portion of the growing season when we receive our most precipitation on average. This helps lower our irrigation pumping requirements for these crops.

I also like this rotation from an agronomic perspective. I think this rotation will work well for the crops we grow. Planting our winter wheat following field pea harvest allows us to get the winter wheat planted in a timely fashion. There also seems to be a synergism between winter wheat following the field peas where the winter wheat tends to have high yields.

I also like this rotation with the corn following the edible beans. The corn gets off to a better start by planting the corn into the edible bean stubble as opposed to planting the corn following the winter wheat stubble like we used to do. I think we will see higher corn yields with this new rotation.

The field peas tolerate the cooler temperatures when we plant them into the corn stubble in the early spring. We also graze the corn stubble to eliminate some of the corn residues. The edible beans are planted into the diverse forage stubble which has been grazed. This allows us to manage the winter wheat stubble and forage crop residues as well. We use livestock within this system to control the amount of residues we are planting into.

I also like the diversity this crop rotation provides from a soil microbe standpoint.

By planting all four crop types we are increasing the diversity and populations of soil microbes in the soil.

As we gain more knowledge of what these microbes can do for us I think this diversity will become increasingly important.

I think water conservation requires a systems approach to get the most out of our water resource.

This systems approach requires soil that performs at a high level. This approach also requires careful consideration to the crops you are growing within your crop rotation.

Next week we’ll look at more components to our systems approach to waterconservation that we are utilizing on our farm.

We are looking at all aspects of water conservation to lower our irrigation pumping requirements.