Manitoba Agriculture Food and Rural Initiatives is encouraging farmers to consider all options for balancing phosphorus fertilizer application with removal by crops, focusing on the least expensive first.
The Manitoba Livestock Manure and Mortalities Management regulation was amended in 2006 to include limits on the application of livestock manure fertilizer based on its phosphorus content.
Because manure contains higher levels of phosphorus than nitrogen and plants use more nitrogen, phosphorus based manure application limits, compared to nitrogen based, can increase land base requirements for spreading from two to six times.
Provincial landscape stewardship specialist Marla Riekman notes producers have range of options.
There are a number of different strategies.
Always important to note that the strategies need to start with the least costly first because there’s no point in going down the line and looking at the most expensive options when really you could take shorter steps and cheaper steps to start with.
We first want to look at feed, looking at minimizing feed wastage and then looking at maybe decreasing the phosphorus content in the feed and, from then, we step down to maintaining zero phosphorus import into the land, maybe not importing phosphorus fertilizer if you don’t need it or staying down to a level of just starter phosphorus early in the spring.
From there we would look at increasing our crop removal of phosphorus and then maybe having to look at increasing our land base so that we have more land to spread the phosphorus on and finally, if that doesn’t quite cut it, we might have to start treating the manure to reduce the amount of phosphorus.
Riekman says, while manure treatment is an excellent option, we have to remember we’re not removing phosphorus, just moving it.
She suggests, because that’s such an expensive technology, it’s important to look at cheaper options such as changing feeding strategies, reducing feed wastage and different cropping strategies first.
Source: Farmscape.Ca
