Influence of applications of sodium molybdate and ground limestone on a newly sown pasture

Abstract

On a newly sown pasture suitably treated with superphosphate four replications of applications of ground limestone at 0, 1, 5, 10, 20, and 40 cwt were set out; across these limed strips sodium molybdate at 0, 1, 2 and 4 oz per acre was applied, giving 24 treatments per replication. At low rates of liming, sodium molybdate increased clover growth more than at high rates; there was no advantage in applying more than 2 oz sodium m::.lybdate per acre. Increasing the rate of application of limestone improved the growth of the pasture even in absence of molybdate. Three ye:us after laying down, all plots carried the same amount of fodder in the spring. Implic3.tions of this result are discussed. Nitrogen, phosphorus, and calcium contents of white-clover leaflets varied relatively little with treatment. Manganese content was reduced by liming, but was little al~ered by variation in rate of application of molybdate. Mangal!ese decreased as molybdenum content increased. A logarithmic relationship between manganese content and rate of use of limestone was found. Molybdenum content was increased by successively larger applic::ttions of ground limestone in the absence of molybdate treatment, and by use of sodium molybdate. Logarithmic relationships between molybdenum content of white-clover leaflets and rate of application of sodium molybdate and also rate of use of limestone were found. pH value and exchangeable calcium of the soil were increased by use of limestone, but citric-soluble phosphorus and potassium and exchangeable potassium and magnesium were reduced by such treatment. These results are important in relation to interpretation of analytical data in advisory work.

Effects of lime on pasture production on soils in the North Island of New Zealand 5. Description of a lime recommendation scheme

“…comm.) but, despite this, liming generally decreases soil exchangeable-Mg (Askew et al 1958;Edmeades 1982). These results suggest that liming may increase the losses of Mg and hence increase the need for fertiliser Mg on some soils.…”

“…These results endorse Connell's (1931) claim, "that lime is not a substitute for fertiliser" -in this instance, P. It would be unwise, therefore, to recommend to farmers to reduce P inputs as a result of liming. The interaction between lime and Mo is well understood and documented in New Zealand (Davies 1951;Cullen 1955;Askew 1958;During 1961During , 1962During , 1972. Because of this interaction and the negative effect of Mo on copper (Cu) availability, as discussed in the section below, caution is necessary if both lime and Mo are applied together.…”

Effects of lime on pasture production on soils in the North Island of New Zealand

“…Following this discovery, many field trials were carried out to investigate the relationship between liming and the availability of soil Mo (During 1972). These trials showed that many soils were Mo deficient and that small quantities ofMo could greatly reduce the need for lime on many soils (Davies 1951;Cullen 1955;Askew et al 1958;During 1961During , 1962During , 1972. As a result of these trials, During ( 1961During ( , 1962 Woodcock (1936) remained unchanged.…”

Effects of Lime, Nitrogen and Phosphorus on the Response of Ladino Clover to Molybdenum

“…responses do not occur if lime has been applied; finally there are also some soils on which Iime mav have little or no effect on the response to molybdenum (1,5,7,8, 10, 12, 15,16)-Similarly, the use of phdsphorus may or may not increase molybdenum de-ficiency (+, 12, 19).' Th; phosphdrus-moiybdenum interaction may even go the'other way,'since r\rlirldei (rS) and'Askew (6) have dernonstrated ihat the use of molybdenum could reduce the need for phosphorus. However, the reports seem less conflicting on the subject of nitrogen-molybdenum relationship, especially when restricted to legumes.…”