‘molly’ isn’t needed in large amounts, but legumes like clover need it to help fix ni­tro­gen.

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6YouAn­i­mals don’t put nu­tri­ents back into the soil evenly. This is why your pas­ture will be dif­fer­ent heights, as there will al­ways be more growth above a dung or urine patch.

But a healthy pas­ture will be com­posed of a con­stant amount of clover right through the pas­ture, and the colour should be a uni­form dark green. When Doug goes onto a farm as a con­sul­tant, he groups pad­docks by their sim­i­lar­i­ties, based on to­pog­ra­phy (eg steep, flat) and other sim­i­lar­i­ties, then marks out soil test sites so he can recheck the same places ev­ery year. While he’s test­ing the dif­fer­ent ar­eas, he’s also mak­ing a note of the qual­ity of the clover us­ing a clover-only herbage test where it is strug­gling (not near urine or dung patches). The two com­bined give a much bet­ter story of what is go­ing on in the soil than just a soil test.

Doug says hav­ing a mon­i­tor­ing pro­gramme of some kind like an­nual soil tests, and clover leaf and mixed herbage tests, is a very small cost in re­la­tion to an an­nual fer­tiliser spend, but can make a huge dif­fer­ence to the health of live­stock, soil fer­til­ity, and the prof­itabil­ity of the land. When you do a soil test there are all sorts of things you can choose to test for: • ph • phos­pho­rus • potas­sium • cal­cium • mag­ne­sium • sodium • sul­phate sul­phur

But Dr Ed­meades says one of the most im­por­tant to in­clude is the test for or­ganic sul­phur, the ma­jor test for mea­sur­ing long-term sul­phur re­quire­ments (as it makes up 95% of sul­phur in soil). In­stead peo­ple tend to tick the box for avail­able sul­phate sul­phur which varies hugely and only rep­re­sents around 5% of what’s im­me­di­ately avail­able to plants. Re­ac­tive phos­phate rock (RPR) was in­tro­duced in the late 1980s as a cheap (by 30% per tonne) and ef­fec­tive al­ter­na­tive to sol­u­ble fer­tilis­ers like su­per phos­phate. The the­ory was, it takes longer to break

When Doug is de­vel­op­ing a nu­tri­ent pro­gramme for a farm, he cre­ates what he calls an eco­nomic op­ti­mi­sa­tion plan and it’s al­ways based on how much phos­phate a prop­erty re­quires as it’s the most ex­pen­sive in­gre­di­ent (about $3/ kg). He checks the Olsen P range, and then brings all the other nu­tri­ents up to the level where they’re not lim­it­ing the ex­pres­sion of the phos­phate. Molyb­de­num (pro­nounced mol-lib-de­num) is a trace el­e­ment and isn’t needed in large amounts, but legumes like clover need it to help break down ni­tro­gen gas into protein as part of their ni­tro­gen­fix­ing abil­i­ties.

But put too much on and it pre­vents util­i­sa­tion of cop­per in live­stock. When molyb­de­num was first dis­cov­ered, farm­ers put on a lit­tle, got a great re­sponse and so quickly in­creased the amounts they used. When they got cop­per de­fi­cien­cies, they then went back too far the other way and stopped us­ing it. Doug says it’s only now that farm­ers are re­bound­ing back to the cor­rect use of ‘molly’.

The best way to test for molyb­de­num is to take clover and mixed herbage sam­ples.

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