Premium
An investigation of problems of sward improvement on deep peat with special reference to potassium responses and interactions with lime and phosphorus
Author(s) -
FLOATE M. J. S.,
RANGELEY A.,
BOLTON G. R.
Publication year - 1981
Publication title -
grass and forage science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.716
H-Index - 56
eISSN - 1365-2494
pISSN - 0142-5242
DOI - 10.1111/j.1365-2494.1981.tb01543.x
Subject(s) - lime , pasture , phosphorus , agronomy , peat , fertilizer , nutrient , potassium , persistence (discontinuity) , grazing , field experiment , zoology , environmental science , chemistry , biology , ecology , geology , paleontology , geotechnical engineering , organic chemistry
In experiments to determine the minimum fertilizer requirements for improved pasture on deep peat, yields were initially low and declined rapidly. Within 2 years persistence of sown species was poor when only 2·5 t lime ha ‐1 was applied. Analytical data suggested that K deficiency and low soil pH were contributory factors. When K was omitted from a composite nutrient solution, clover yield was reduced by 50% when 2·5 t lime ha ‐1 was applied but was not significantly reduced with 5·0 t lime. Clover alone produced little response to either P or K separately, but highly significant positive interactions were recorded. Clover, but not ryegrass, responded to K topdressing in field cut‐herbage experiments. There was a 3‐fold increase in ryegrass yield with combined P and K topdressing under grazing; 10 times more N and K were recycled in urine on this treatment than on the control. It was concluded that at least 5·0 t lime, 60 kg P and 80 kg K ha ‐1 are required for pasture establishment and that soil pH should be maintained above 5·0 to minimize K requirements. The significance of nutrient cycling and of lime × K and P × K interactions is discussed in relation to the persistence of sown species and the maintenance of improved swards on deep peat.