Document Type

Thesis - Open Access

Award Date


Degree Name

Master of Science (MS)


Plant Science

First Advisor

Paul E. Fixen


Fertilizer placement is generally more important for phosphorus than other nutrients. Phosphorus is an immobile nutrient. Unlike nitrogen which is mobile and transported by mass-flow, phosphorus is transported by a much slower process known as diffusion. Phosphorus fertilizer also reacts with soils to form products which are only slightly soluble. The greater the soil-fertilizer contact the less chance there is of the phosphorus remaining in a soluble form. Most plants have their highest requirement for phosphorus during the early stages of growth. The first part of the growing season is usually when environmental conditions are less than optimum for plant growth. Phosphorus placement could become more important as reduced tillage becomes increasingly popular in many areas of the United States. Reduced tillage is becoming more popular because of its possible economic, ecologic, and conservation advantages. Since only a small portion of the soil surface layer is tilled in some reduced tillage systems, phosphorus fertilizer incorporation may be very limited. Normally, phosphorus has been broadcast on the surface and incorporated with primary or secondary tillage. But with some reduced tillage systems both of these operations could be eliminated. The basic objective of this study was to compare several different phosphorus placement methods for corn, soybeans and oats.

Library of Congress Subject Headings

Fertilizers -- Research
Phosphatic fertilizers



Number of Pages



South Dakota State University


No Copyright - United State