Effect of nutrient seed coating on the emergence and early growth of perennial ryegrass

Abstract

Perennial ryegrass (Lolium perenne L.) seeds were coated with either lime, reverted superphosphate plus nitrogen as isobutylidene diurea (RSN), or partially acidulated rock phosphate plus sulfur (ESPARP). In one experiment emergence rates and total emergence were calculated by fitting Mitscherlich-type curves to the data and then conducting statistical tests on the three parameters found for each curve. There was a significant interaction between soil moisture and coating treatment for all three parameters. In a glasshouse experiment, the same coated and uncoated seed treatments were sown either in soil supplied with nitrogen, phosphorus and sulfur or in soil with nutrient deficiencies of either N, P, or S or NPS, and the early growth of the plants and their P and N uptakes were studied. The two nutrient-coated treatments (RSN and ESPARP) produced more tillers and dry matter yields of roots and shoots than did lime-coated or uncoated seed when grown in soils deficient in P, S or NPS. Nitrogen deficiency reduced yields of all plants, even those derived from RSN seeds. N uptake in the RSN treatment was not significantly different from the ESPARP treatment, indicating that the N in isobutylidene diurea was not available to the plant.