Improving slurry value through Nitrogen retention
Innoculant treated slurry R&D findings
Livestock farmers can increase grass silage dry matter levels by up to 20%, help cut their total fertilizer bill, and reduce soil nitrate levels if they treat their slurry tanks this winter with an innoculant, according to recent research carried out at Myerscough College with Liverpool John Moores University. Slurry Bugs treated slurry showed savings of £4,100 per annum in nitrogen fertilizer costs, based on a 150 cow herd producing 1,200 tonnes of slurry per winter, and an average nitrogen retention of 70%.
New trials were carried out on third cut silage swards at Myerscough College’s dairy unit and featured three treatment plots; slurry treated with Slurry Booster innoculant, slurry treated with Slurry Booster plus 65 units N fertilizer and a control of untreated slurry. Each treatment was applied to RB209 requirements at 70m3N/ha during July month, and replicated four times.
“When Slurry Booster treated slurry plus fertilizer was applied to swards this yielded on average 17.7t of fresh grass per ha, a value 10% higher than that observed when innoculant treated slurry only was applied, and 40% higher than the control,” explained Myerscough College farm manager, Roger Leach. “With reference to dry matter content, swards treated with Slurry Booster innoculated slurry showed the highest dry matter percentage grass of 20.3%. More importantly, total dry matter of grass yielded from all treated slurry plots returned the largest grass dry matter yield of 3.25 tonnes per hectare” See table 1.
Table 1: Comparison of the three treatments on grass yields and residual content
|
|
Untreated slurry (control) |
Innoculant treated slurry |
Innoculant treated slurry + 65 units N |
|
Grass yield (t/ha) |
12.6 |
16 |
17.7 |
|
Grass DM content (%) |
17.1 |
20.3 |
16.1 |
|
Grass DM yield (t/ha) |
2.15 |
3.25 |
2.85 |
|
Grass sugar content (kg/t) |
49.6 |
60 |
59.3 |
|
Residual Soil Value |
|
|
|
|
N as nitrate (mg/kg) |
2.9 |
2.36 |
2.6 |
|
Ammonium nitrate (mg/kg) |
0.74 |
0.54 |
0.65 |
|
Phosphorus (mg/l) |
3.8 |
4.8 |
4.8 |
|
Potassium (mg/l) |
185 (2+) |
161 (2-) |
155 (2-) |
“In addition, all plots receiving treated slurry returned a higher grass sugar content when compared with the control. The resulting silage from the higher sugar grass therefore has the potential for an improved fermentation, and subsequent palatability for cattle.”
“Finally, when the soil was tested for residual N 1 week after the cuts were made, the plots to which innoculant treated slurry had been applied recorded levels lower than the control. This suggests that nutrient uptake by the plants has been more efficient as a result of the Slurry Bugs treated slurry.”
Liz Russell of Envirosystems who sponsored the trial says: “These findings confirm the potential opportunities available to all farmers to boost the nutrient value of their slurry and subsequently forage value by introducing one simple minimal cost treatment.
“The Slurry Booster system comprises two active ingredients, SlurryBugs contain naturally occurring bacteria which metabolise ammonia, reducing odour and preserving N content. These same bacteria also produce enzymes that breakdown the organic material in slurry,” she explains. “When introduced to slurry together in the lagoon, they supply an innoculation that improves the nitrogen concentration and also reduces the need to mix by ensuring efficient conversion of solid material in to liquid nutrient.
“Introducing the innoculant to slurry offers other valuable spin offs. Apart from cutting the fertilizer bill, the trials demonstrated that soil nitrogen and potassium levels were reduced when applied slurry had been treated with Slurry Bugs. This indicates that the soil nutrient availability and resulting plant uptake can be enhanced following the application of Slurry Bugs treated slurry. Also, since this harvest was the last to be taken before the winter months, the lower residual levels of soil N are important in the prevention of risking winter leaching.”
Call Envirosystems to find out more: 01772 860 085
Or fill in our enquiry form HERE and we'll contact you!!
