Some effect fluid‐sowing, pre‐germination, irrigation and soil covering on the establishment and growth of seedlings of white clover slot‐seeded into permanent pasture

Abstract Seeds of white clover (Trifolium repens) were sown alone or in fluid, or pre‐germinated in fluid on to the soil surface of slots cut in an old Agrostis/Festuca sward. Seeds were left uncovered or covered with a thin layer of soil and irrigated from the outset or after 14 days delay. With irrigation from the outset, seedlings established soonest from pre‐germinated seeds but final percentage establishment ranged only from 50 to 63% for the three states of seed. With delayed Irrigation, however, few pre‐germinated s1 survived and although germination of dry seed was delayed, final percentage establishment was unaffected. Soil covering increased establishment slightly. The number of leaves per seedling was greatest with pre‐germination and early irrigation and least with pre‐germination and delayed irrigation. Delayed irrigation also decreased the number of leaves per seedling for seedlings grown from dry seed. The effects of early irrigation persisted so that at 84 days it significantly increased total yield of clover from all three states of seed, on average threefold, but much more from pre‐germinated than from dry seed. Soil covering greatly increased yield, especially where irrigation had been applied from the outset. The interaction of early irrigation and soil covering was even more pronounced for stolon weights, and stolon growth of Individual seedlings appeared to benefit more from soil covering than from early irrigation. The results showed the importance of early seedling emergence, but no advantages of fluid sowing per se. They also indicated large overall beneficial effects of early irrigation and its additive interaction with soil covering.