By Bob Amstrup, Northwood, ND

My interest in soil conservation began in the early 1980’s when drought and severe wind erosion struck our area. I asked myself at that time how am I ever going to lower my production costs, when my #1 resource is filling the ditches? My soil loss was due primarily from black summerfallow and I determined then that there had to be a better way of managing set aside acres.

The idea of using sweet clover as a means to stop soil erosion came from the many conversations with retired farmers in our community who routinely used clover as their main source of nitrogen before the advent of commercial nitrogen. They encouraged and cautioned me at the same time.

The encouraging aspects of sweet clover are as follows:

• It can be seeded with a companion crop
• It can produce up to 150 pounds of nitrogen per acre
• It can produce up to 2-4 tons of top growth that can be used as green manure or livestock feed
• It has a tremendous root system that can penetrate up to 8 feet and improve soil tilth to allow for better water infiltration and root development in subsequent crops
• It can assist bin reclaiming saline/alkali areas of a field
• Including sweet clover in a crop sequence will break disease and insect cycles
• In a min-till or 0-till program, sweet clover will stop soil erosion.

• Sweet clover is a high water use crop
• Sweet clover is a biennial, therefore under a conventional program, it will require a producer to take that acreage out of production two years in a row
• Under the right circumstances it will compete with a companion crop
• There are few if any pesticides that are labeled to control weeds in sweet clover.

To avoid having the sweet clover compete with a companion crop, and more importantly to avoid having to enter a field into set aside two years in a row, I 0-till the sweet clover directly into standing barley stubble tight after harvest. It is crucial to have the seed in the ground by August 10^th so the plant will be advanced enough to survive the winter. The seeding is done with 20 feet of conventional John Deere 9350 drills equipped with John Deere fine seed boxes. By seeding into the ground rather then broadcasting on the surface, the seeding rate can be cut by four to six pounds per acre.

The following year assuming a good catch, I will let the crop grow to full bloom. The crop is then killed by using a 20 foot corn shredder leaving 4-6 inches of stubble. The shredder will leave a blanket of fine particles covering the ground helping to stop evaporation and soil runoff from hard rains.

To help start the decomposition of the residue, I chisel plow the field twice, still leaving approximately 60% residue cover by freeze-up.

To prepare the field for wheat the following spring, one shallow pass with a field cultivator leaves a good firm seedbed. The old sweet clover stubble seems to disintegrate and incorporate nicely in the soil, with just this one pass.

1. The demands of harvest can be so great that more often then not I have missed that all

important August 10^th seeding date. The seeding will then be done the following

spring, therefore taking that field out of production for cash crops two years in a row.

2. Sweet clover seedlings cannot grow in chaff rows! We have to get that chaff spread

behind the combine.

3. Soil tests taken the fall of a sweet clover/fallow year, show the expected increase in

soil N. but also show a sharp drop in soil P. Phosphorus management the following

crop year is very important.

Some things I would like to try in the future are 0-tilling cereal grains into sweet clover sod. Using tram lines to broadcast sweet clover before harvest. Rotating dry beans after sweet clover.

I am excited about the potential of this legume to not only stop erosion, but to become a building block for long lasting soil productivity.