By Michael Brown, AAg, CCA, Crops Extension Specialist, Humboldt
The four Rs of nutrient stewardship – right source, right rate, right time and right place – have been pillars of nutrient management in farming for over 30 years. However, it is only in the past decade that these 4Rs were built into a global framework based on science to guide those involved with nutrient stewardship.
Many of the fertilizers we use today continue to be heavily researched. Ongoing research seeks to understand best management practices when it comes to application and the reactions they undergo when they become plant available or lost to the environment from volatilization, leaching, runoff, etc. Other areas of research are also expanding with topics like improving productivity and profitability, improving fertilizer use efficiency, better crop and soil management, environmental protection and economic and social and environmental sustainability receiving increased attention.
Most producers already have some type of 4R nutrient stewardship on their farms, even if they're unaware of the official practice. Do you conduct soil tests on your farm and determine the fertilizer rate required on that land for a certain crop? If yes, you are a 4R steward because you are determining the right rate to put down without potential for excess nutrient loss to the environment. Do you band your phosphorus? If yes, you are a 4R steward because phosphorus can be lost to wind or water erosion on the soil surface and pollute waterways, and you put it in the right place.
A lot of the practices involved in 4R nutrient stewardship are appealing to producers because they maximize farm margins, so we see benefits not just for net farm income, but for the environment as well.
Although each R will have its own respective list of practices to consider, they all must be taken into consideration, even when thinking about each one individually. For example, you may be considering two different types of nitrogen fertilizer sources, but their compositions would mean completely different rates at different times at different placements.
On a provincial level, Saskatchewan has over 37.1 million acres of cropland. In 2016, Fertilizer Canada signed a memorandum of co-operation with the Government of Saskatchewan to work together on the implementation and adoption of 4R nutrient stewardship fertilizer application practices.
The Fertilizer Institute has been working collaboratively with the International Plant Nutrition Institute, the International Fertilizer Association and Fertilizer Canada to advance the 4R nutrient stewardship initiative.
The Ministry of Agriculture is working to support the agriculture sector's long-term resiliency. One of the ministry's measurable objectives is to increase total farmland managed using 4R to 25 per cent, or nine million acres, by 2025. This is just one of many of the measurable targets in the Government of Saskatchewan's Prairie Resilience: A Made in Saskatchewan Climate Change Strategy, which includes agricultural-related measures and targets intended to strengthen Saskatchewan's ability to adapt, and even thrive, within a changing climate.
The ministry's regional crops extension specialists recently held a 4R webinar series to go over the basics of each of the 4Rs. The recorded webinars can be found on our Webinars page.
For more information on 4R nutrient stewardship, please contact the Agriculture Knowledge Centre at 1‑866‑457‑2377.