The harrow also helps level the soil for planting. Heavy stones are usually placed on the harrow to keep the spikes in the soil when unfavorable soil conditions exist. Another kind of harrow, the spring-tooth harrow, has flexible teeth that work better over roots and stones. Manure Spreader Waste from horses, cattle, and sheep are spread on the fields with a manure spreader. Manure is mixed in the soil by plowing or disking to provide natural plant food and nitrogen for the crops.
Manure also supplies humus which helps the soil hold water.
The road grader was used to build and maintain earthen roads. The grain drill is used to plant small grain seeds such as barley, oats, wheat, or rye. As horses pull the planter up and down the field, the drill drops the seeds, evenly spaced in rows, distributes fertilizer, and covers the seeds with soil. Corn Planter Two rows of corn are planted at a time with a horse-drawn corn planter. The planter drops and covers the corn seed, evenly spaced in rows.