24 July 2001
Manure and slurry applications
Can I apply Farmyard manure and slurry and still lo-till?
There are a number of variables that need to be considered here which affect the outcome of method chosen.
First and foremost the type of manure being spread and how fresh it is. Surface spreading and ploughing down fresh slurry or FYM greatly reduces losses N through volatilisation and is neighbour friendly also!
However for maximum effect this operation should take place within 4 hours of spreading. Leaving such material on the surface in advance of a lo-till regime will lead to losses unless the material has been stacked or composted for a period, in which case most gaseous losses will have already occurred.
In this situation, surface application should not present a problem subject to normal or light application rates. However ideally some surface incorporation of this material (I use discs followed by a set of rolls ) will encourage breakdown and flush any weed seed coming in through the manure and in the soil surface.
In soils which have been subjected to lo-till regimes for a number of years, breakdown can be very rapid because of the enhanced level of microbial activity in the soil surface and greater earthworm numbers, which help to distribute the manure through the soil.
Ploughing of mature FYM places the material deep into the soil where oxygen levels are low and this can lead to dinitrification and loss of N. So, as with all things lo-till, plan a strategy to take account of your circumstances.