Submitted to: Crop Science
Publication Type: Peer reviewed journal
Publication Acceptance Date: 2/2/2003
Publication Date: 4/30/2003
Citation: STEINER, J.J., ALDERMAN, S.C. RED CLOVER SEED PRODUCTION: VI. EFFECT AND ECONOMICS OF SOIL PH ADJUSTED BY LIME APPLICATION. CROP SCIENCE. 2003. v. 43(2). p. 624-630. Interpretive Summary: Can addition of lime increase soil pH levels and reduce the amount of root rot found in red clover seed production fields? If so, seed yields and the stand life of red clover seed fields could be increased which would amortize establishment costs and increase net profit to farmers. The effects of two-and-one-half and five tons of lime per acre on a pH 5.5 soil was studies. The effects on seed yield by the different soil pH levels as well as normal and delayed herbage removal timing and first and second year stand ages were looked at. First year seed yield increased with increasing lime amount, but second seed year yields were unaffected. Interestingly, root rot incidence increased with increases in soil pH that is opposite to reports for other crops. When the added expense for adding lime is considered, there is no benefit to adding lime. Since there was no benefit from lime on the following wheat rotation crop, lime application cannot be justified solely for the benefit of red clover seed production.
Technical Abstract: Red clover (Trifolium pratense L.) is an important forage legume primarily grown for seed is western Oregon, USA. Stand decline can occur from root rot disease caused by Fusarium solani. Increasing soil pH by lime application has been shown to reduce disease incidence in numerous other crops. The purpose of this research was to determine the effect and economics of soil pH on red clover seed production and root health. Investigated were three lime rates and the effects of normal and delayed spring herbage removal time and first and second-year seed crop on seed yield and economic return. Soil pH after the three lime application was 5.6, 6.1, and 6.4, respectively. Clover plants in the untreated control were generally chlorotic and shorter than plants in the two lime treatments prior to herbage removal in spring 1994. First-year seed yields were greater with than without lime, but second year yields were unaffected. Soil pH did not affect clover phytomass after herbage removal, and did not affect rotation crop wheat straw and grain yields. Soil pH was correlated with clover root diameter and root rot index. Within the range of soil pH values examined, neither lime amount produced a seed yield increase that was more economical than the untreated control. For the range of soil pH conditions, without improved root health, and in the absence of any affect on rotation crop yield, lime application cannot be justified solely for the benefit of red clover seed production.