Seeding Year Harvest Management of Red Clover

Abstract

Red clover (Trifolium pratense L.) is widely grown in the Pacific Northwest as a forage crop and in rotations for soil improvement. Management practices which maximize red clover yield and quality during the seeding year remain unresolved. The objective of this research was to determine the effect of seeding date and seeding-year harvest schedules on total dry matter (DM) yield, forage quality, nutrient yield, economic returns, and persistence of red clover. Red clover was seeded without a companion crop on different dates during the spring and subjected to one or two harvests during the seeding year. An initial harvest was taken 40, 60, or 80 d after emergence. The two-cut treatments were harvested again at early flower or 6 wk before the mean killing frost date, whichever came first. Red clover harvested twice in the seeding year averaged 93 and 96% greater DM and digestible dry matter (DDM) yields, respectively, than red clover harvested once. Delaying the single-harvest treatment from 40 to 80 d increased DM and DDM yields by 1339 and 854 lb/acre, respectively. Dry matter yields were not different among planting dates when a single harvest was made during the seeding year. Planting on or after 9 May at Moscow, ID, or 25 May at Sandpoint, ID, and taking two seeding-year harvests reduced DM yield the following year by 1338 or 1482 lb/acre compared with earlier planting or taking a single harvest, respectively. Red clover persistence did not differ among treatments. Under irrigated conditions at Moscow, net economic returns per acre were maximized by seeding in mid-April, delaying the initial harvest until 80 d after emergence (late flower stage of development), and taking a second harvest during the seeding year. At Sandpoint, under nonirrigated conditions, optimum economic returns were realized by planting in late May and taking only a single harvest during the seeding year. Seeding date and harvest management and their interaction with such environmental conditions as temperature and precipitation during the seeding year can alter red clover productivity and optimal management over the 2-yr life of the stand.