FAQ: Organic Manures
Q. How long should one leave between spreading fertiliser N and slurry?
Slurry applied on fertilizer N creates ideal conditions for denitrification, i.e., anaerobic conditions and high carbon compounds. It is recommended to leave 4 to 7 days before or after slurry spreading for application.
Q. How long should one leave between spreading lime and urea?
Lime increases soil pH which increases rate of volatilisation of ammonia. Do not spread urea for 3-6 months after lime application.
Q. How long should one leave between spreading urea/ slurry and lime?
Where urea is spread in advance of lime it will eliminate the risk of N loss through volatilization. It is recommended to leave 10 days between applying urea and lime.
Q. What’s the fertiliser value of 1,000 gallons of cattle slurry?
It is equivalent to a 50kg bag of 6-5-30 (N, P & K)
Q. To maximise the recovery of N in high N manures such as pig slurry / poultry manures when should they be incorporated / ploughed in?
Aim to plough in within 3 to 6 hours after application to maximise N recovery
Q. What is the difference between the total nutrient content and available nutrient for organic manure such a cattle / pig slurry or FYM?
The total N in Cattle Slurry is 3.6kgN/tonne and for example when applied in the springtime it is deemed to be 25% available therefore 0.9kgN/tonne available N.
The total N in Pig Slurry is 4.2kgN/tonne and for example when applied in the springtime it is deemed to be 50% available therefore 2.1kgN/tonne available N.
Q. What is the availability of P and K in organic manures when applied on low fertility soils (Index 1 and 2)?
P is deemed to be 50% available and K 90% available
Q. What is the benefit of applying cattle slurry in the springtime compared to mid-summer?
Highest crop demand in the springtime plus better N recovery 25% ‘v’ 5% when applied by splash plate.
Q. What are the benefits of applying slurry by trailing shoe application over splash plate?
The trialling shoe has many benefits from reduced grass spoilage, application of slurry to higher grass clovers to improved N recovery from liquid slurries.
Q. Why is it important to incorporate animal slurries as soon as possible after application?
Rapid incorporation of high N manures (pig/poultry manures) reduces N losses and improves available N for crop uptake.
Q. What effect will the trailing shoe application technique for cattle slurry have on the N availability compared to the splash plate method?
Splash plate applied 6 units N per 1,000 gallons
Trailing shoe 10 units N per 1,000 gallons
Q. Which manure type is most suited to grazing ground?
Pig slurry has a ratio of P: K (1:2/3) which is ideal for grazing ground as it has a good balance of N- P-K (19-7-20).
Q. Which manure type is most suited to silage ground?
Cattle slurry has the correct P:K ratio (1:6) for silage swards for example N-P-K 6-5-30
Q. What are the main factors affecting the nutrient content of an organic manure?
Animal type / diet / water dilution / level meal feeding
Q. What effect has cattle / pig slurry on earth worm numbers?
No effect once applied at recommended rates
Q. How do I determine the quantity of lime required to correct soil pH?
A. A recent soil report will show the rate of lime required depending on the soil type, soil pH and crop type.
Q. How long will it take lime to work?
A. The fine ground limestone (35%) will work relatively fast, and the course lime particles will react more slowly and help maintain soil pH for a number of years.