The residual effect of molybdenum fertilizer on growth of tropical pasture legumes in a sub-tropical environment

Abstract

The response of several tropical legumes, grown with Panicum maximum cv. Gatton, to an initial application of molybdenum as molybdenum trioxide was studied over a five year period at six sites in south-eastern Queensland. The most responsive legumes were Glycine wightii cv. Tinaroo and Desmodium intortum cv. Greenleaf, followed by Macroptilium atropurpureum cv. Siratro and Medicago sativa cv. Hunter River, with Lotononis bainesiicv. Miles and Stylosanthesguianensis cv. Cook being least responsive. Sites differed markedly in magnitude of legume response. For example, the most responsive site required 200 g ha-1 molybdenum over five years for maximum growth of Siratro whereas there was no response of Siratro to molybdenum application at another site. There was no difference between surface-applied molybdenum trioxide, molybdenum trioxide applied to the seed pellet and surface-applied sodium molybdate in their residual effects on legume growth. Response of the grass to molybdenum treatment was generally similar to legume response and nitrogen concentrations in legume and grass increased with yield.

Mineral constraints to nitrogen fixation

“…Specific involvement has been claimed in cases where nutrient applications increase both legume growth and nitrogen concentrations in plant tops. Examples of increases in nitrogen concentrations of symbiotic legumes following correction of nutrient deficiencies have been reported for Ca in T. subterraneum (Banath et al,, 1966;Loneragan, 1959); Co in Lupinus angustifolius (Chatel et al, 1978); Cu in T. subterraneum (Greenwood and Hallsworth, 1960;Snowball et al, 1980) and T. repens (Van der Elst et al, 1961); Mo in T. subterraneum (Anderson and Spencer, 1950a) and in Macroptilium atropurpureum, Glyeine wightii, Desmodium intortum and Lotononis bainesii (Johansen et al, 1977); P in T. subterraneum (McLachlan and Norman, 1961) and Stylosanthes humilis (Gates and Wilson, 1974); S in T. subterraneum (Anderson and Spencer, 1950b), D. intortum and L. bainesii (Andrew, 1977b), and S. humilis (Jones et al, 1971) and Zn in M. sativa (Lo and Reisenauer, 1968). However, such results should be interpreted with caution since increases in plant nitrogen concentrations may also reflect changes in plant structure (e.g.…”

Phosphorus Uptake and Dry Weight of Stylo and White Clover as Affected by Chlorine1

“…The Fe concentration was increased from 2 p.M to 20 p.M following the advice of Asher (personal communication). Levels of 0.08 p.M Mo (white clover) and 0.04 p.M Mo (stylo) were used since Johansen et al (1979) have demonstrated an increased critical level of Mo in white clover compared to stylo.…”

Layered Double Hydroxides as Slow-Release Fertilizer Compounds for the Micronutrient Molybdenum

“…Efficient Mo supply is key with regard to Mo fertilizer application, not only from the perspective of providing sufficient plant-available Mo but also from that of efficient resource usage and minimization of dissipative Mo losses linked to fertilizer application . Yet, soil application of soluble Mo fertilizers is often associated with a low fertilizer use efficiency due to either fast MoO 4 fixation in soil after release from the fertilizer or to losses from the topsoil by leaching. , With foliar application, these issues can largely be avoided, which therefore also often results in higher Mo fertilizer effectiveness in comparison with soil application . However, foliar application is also labor-intensive, and its effectiveness can be very dependent on the application time …”

“…13 Yet, soil application of soluble Mo fertilizers is often associated with a low fertilizer use efficiency due to either fast MoO 4 fixation in soil after release from the fertilizer or to losses from the topsoil by leaching. 14,15 With foliar application, these issues can largely be avoided, which therefore also often results in higher Mo fertilizer effectiveness in comparison with soil application. 16 However, foliar application is also labor-intensive, and its effectiveness can be very dependent on the application time.…”