Results of an experiment at Woburn testing farmyard manure and N, P and K fertilizers on five arable crops and on a long ley:II. N, P and K removed by the crops

Abstract
1. From 1960 to 1964 an experiment at Woburn, Bedfordshire, measured yields and the amounts of N, P and K removed by five arable crops (barley, grass-clover ley, potatoes, oats and sugar beet) and by a long ley; each was manured with all combinations of N, P and K fertilizers and with farmyard manure (D) and with both fertilizers and farmyard manure (DN1PK and DN2PK).