Fibrophos Handbook 2015

Phosphate in Fibrophos

OBJECTIVE AND METHOD

ADAS Huntingdon

S.J.Richardson

Ryegrass was chosen as the test crop because sequential cuts allow an assessment of

how quickly nutrients become available as well as revealing their overall availability. Two

soils were used with very low P content. The pH’s were 8.2 and 6.4 respectively. Cuts were

taken whenever the most advanced plants reached 10-12cm in height on each occasion.

Ashed Poultry Litter (Fibrophos) was compared with TSP, Basic Slag and Rock Phosphate.

Observations: Three months after sowing, yield was restricted in the nil treatment

whereas all fertiliser treatments except phosphate rock markedly increased yield.

At that stage, both yield and phosphorus content of the foliage already indicated that

the phosphorus in the Fibrophos was at least as readily available, possibly more so,

than that in basic slag and more readily available than that in phosphate rock.

By cut 6 both yield and phosphorus uptake data for Fibrophos showed it to be superior

to basic slag and rock phosphate. Of more significance however is the evidence that

Fibrophos is as effective as TSP.

The design of the trial included TSP added in steps of 40Kg/ha P

in order to allow the

efficiency of Fibrophos to be assessed: both yield and phosphorus uptake suggest it is

100% efficient within 2 months of application.

Trials have shown that Fibrophos is

a very effective source of phosphate

across a wide range of soil types

throughout the UK. The phosphate in

Fibrophos is more than 80% soluble

in 2% citric acid and half is soluble in

neutral ammonium citrate providing

a long lasting as well as immediate

supply to the growing crop.

Applications to both acid and

alkaline soils have been shown

to increase the available soil

phosphate within one month

and this increase was maintained

for at least 12 months.

Evaluation of Fibrophos as a fertiliser

Conclusion

As a long lasting source therefore, Fibrophos is ideal for raising the soil

phosphate status and maintaining it. Used for this purpose when soil

phosphate is 0 or 1, Fibrophos can be applied at 625Kg/ha (5 bags/acre)

every two or three years depending on crop potential. This will provide

an adequate level of phosphate to ensure full effectiveness of nitrogen.