While New Zealand has a diverse range of soil types, only around 5% are fertile and versatile enough to support food production without significant manipulation. Variable rate lime and precision nutrient management are two important strategies in modern agriculture that can help farmers improve crop yields and reduce environmental impact. 

This approach is particularly important in today’s global economy, where farmers are under pressure to produce more food with fewer resources. By using these techniques, farmers can produce more food with fewer inputs, which is not only good for the environment, but also for the farmers’ bottom line. 

It is possible to have too much of a good thing.  

Accidification of soil occurs naturally, but can also be accelerated by fertilisation practices that decrease soil pH. Plants don’t tend to grow very well if the pH in your soil isn’t quite right. If you read last month’s edition you would have learnt about Yield Mapping and how you can use it to identify the high and low yield areas of your farm. So, how do you fix the low yield areas?  

This is where Variable Rate Lime comes in to play. We are sure you are all aware that Lime affects your PH. Variable rate lime is a technique that involves applying lime to paddocks at different rates based on soil test results. Lime is a valuable amendment for many soils, as it raises the pH and makes other nutrients more available to plants.  

If you have an acidic low pH soil you can add lime to raise pH levels, but lime is a very challenging material to spread due to its fine and non-uniform particle size. Applying too much can also waste product and damage the environment. Lime applied at a variable rate aims to reduce the variability of soil pH levels across the paddock by applying only what’s needed.  

So how do you figure out how much lime is required and where?  

Enter an important tool in your precision ag toolkit – Precision Nutrient Management.  

Precision Nutrient Management allows you to apply the right amount of nutrients only to the area that requires it, as determined by soil sampling. This process gives you a greater understanding of nutrient levels across your farm and the ability to correct any issues. 

Not all soil is the same. Your nutrients could be affected by the area you live in, your soil type, or you could have years of nutrient build-up in your soil from previous farming practices. Soil testing gives you an accurate map of nutrient levels within your paddock. Thanks to GPS technology, the data is accurate and the process is repeatable from the same points in the future. 

Using the soil test results, you can then use variable rate fertiliser allowing you to use fertilisers more efficiently and reduce the soils variability across a paddock. Through this method, both yields and environmental sustainability can be improved, while saving money on nutrients. 

So how does it work?  

We will take samples of soil from across your paddocks to determine their nutrient levels. We then work directly with the farmer or your preferred nutrient advisor team to ensure you are applying the right nutrients in the right places at the right time.  

Short term financial pain for long term gain. No two farms are alike, so until testing is done, you can’t tell what your nutrient levels are and what rates of fertiliser you need to apply to get your nutrient levels at optimum levels for plant growth. After performing tens of thousands of hectares of PNM across NZ, the general rule is that you will have to apply less lime in the first year (because the amount is already too high in most areas) and this will cover the soil sampling costs, with any additional nutrient (P, K etc.) savings being the cherry on top. 

If you don’t overapply or underapply nutrients, your range of nutrients will decrease year after year, and it is during this adjustment period (depending on how often you sample soil and apply lime and fertiliser) that you will achieve the greatest savings. Not only will you save money on fertiliser, but you will also enjoy increased plant growth and health as a result of reducing nutrient limitations. 

Trimble Ag Software and PNM

Using Trimble displays and Trimble Ag Software provides significant advantages in precision nutrient management. The integrated suite of tools and technologies offered by Trimble enables farmers to optimise the application of fertilisers with unmatched accuracy, enhancing crop yields and minimising environmental impact. The software’s advanced algorithms and real-time monitoring capabilities allow for precise variable-rate application, ensuring that nutrients are distributed precisely where and when they are needed most.

With Trimble Displays, Trimble Ag Software, AutoSync & Field_IQ, farmers can streamline their nutrient management workflows and record-keeping, reducing unnecessary paperwork and giving them more time back for doing what they’re best at – feeding NZ and the world.

Ready to take the guesswork out of farm nutrient management and stop blanket rate application? Talk to us today about precision nutrient management.  

Find out more at vantage-nz.com/precision-nutrient-management