The amount of fertilizer you use per acre can have big impacts on your crops and soil health. Too much nitrogen (enriched or chemical fertilizers) can cause toxicity to grow in your plants, which will impair their growth.
Too little phosphorus can deprive your plants of this essential nutrient, leaving them with weak roots that also may not thrive.
Both too much and not enough nitrogen and phosphorous can result in poor plant growth, which can reduce crop yields significantly. This is particularly true during dry seasons when plants need water to flourish.
Fortunately, there are ways to optimize the nutritional value of your soils while still producing quality fruits and vegetables. Here are some tips for how to increase the nutrients in your farm’s food production area and keep it easy to do at home!
Reminder: Although most natural foods such as fruits and veggies already contain what they need, we recommend adding one small package (one tablespoon) of each of these three nutrients per square foot of growing area every two months to maximize the benefits. For example, if you have a 1-acre plot, buy 2 tablespoons of compost, 2 tablespoons of bone meal, and 2 tablespoons of rock powder. Mix them together and apply evenly across the surface. You can check our article here on how to make your own homemade compost to see why having a source of decomposed matter is important to healthy soil.
What is nitrogen?
Nitrogen is one of the most important nutrients for plants to grow well and stay healthy. Plants get their energy from photosynthesis, which requires oxygen and glucose (sugar) as components.
Plants take in air through their roots, then use the sugar and water inside them to produce both carbohydrates and proteins. These are the building blocks of all living things!
The atoms of each component can’t be fully absorbed into the plant without the presence of an optimal amount of free or unbound nitrogen. This is why fertilizer that does not have an adequate proportion of nitrogen is less effective than ones with higher percentages of N.
Too much nitrogen can cause your plants problems though- it may result in leaf burn and death, poor growth or even blight. Too little can mean disease and death at the very least.
General tips: remember that older fertilizers will contain lower levels of nitrogen per kg than newer types. The average person uses about 0.8kg/ac of slow release fertilizer per year, so look up how much nitrogen your specific crop needs to know if it is overdoing it.
What is phosphorous?
Phosphorus is an essential mineral for plant growth. Plants require phosphorus to produce energy through photosynthesis, the process by which they ingest air, light, and water and use it to make their own food.
Phosphorus comes from two main sources: inorganic (or non-chemical) phosphorus such as rock phosphate or calcium phosphate, and organic (skeletal) phosphorus found in foods like eggs, milk, meat, and broccoli.
But how much phosphorus does your crop need really matters! Too little can result in poor plant health and low yields, while too much can be wasted due to excess runoff that contributes to eutrophication — a situation where there are excessive amounts of nutrients in the soil that cause algae blooms and fish death.
This article will help you determine the appropriate amount of phosphorus for your crops.
What is potassium?
Potassium is an element that plays many important roles in your body. It helps regulate blood pressure, aids in muscle contraction, and enables nerves to function properly.
You’ve probably heard of sodium, which is a major contributor to water retention. Sodium can also affect how well you feel and sleep and may even contribute to hypertension or high blood pressure.
But what if I told you that there’s more potassium than sodium in our soil? And what if we didn’t eat enough of it?
That would be bad! Because not only does potassium help keep your heart beating, research shows that eating enough potassium can prevent death due to cardiovascular disease. In fact, some studies suggest that higher intake of potassium reduces risk of mortality by up to 50%!
So why don’t we get enough potassium?
It turns out, we do! Most of us have around 6 grams per day, but most experts recommend at least 8 g/day for healthy people. The average person eats about 3-5 percent of their daily value each day, so to achieve this goal, you’d need to increase your potassium intake by about 30–60 mg every day. (A one tablespoon serving of salsa has about 60mg of potassium!)
And while it might sound like a lot, everyone is different and needs different amounts of minerals to stay healthy. Some people are genetically low in potassium and require less than others to remain healthy.
How much fertilizer should I use?
When it comes to fertilizers, how much you use is dependent on your crops’s growth stages as well as the type of soil you have.
If your plants are in the germination or seedling stage, then you can add more nutrients by adding proportionally higher amounts of both slow-release and quick-release products. This is because they take longer to work so there is not an overabundance of effect at any one time.
When using direct-application forms of nutrition such as granules, spoons, drops and pellets, make sure to go light on the product and spread it around properly. If you like, you can even mix your own blend!
There are several ways to determine when each plant needs its needed nourishment. Using a leaf that has just started to curl and show green coloration indicates need for phosphorus. A yellowed leaf suggests nitrogen deficiency.
General tips: remember that heavier applications may be needed during dry seasons as plants require water and nutritional help to grow.
Too much can be bad for you
The amount of fertilizer you use per acre has a dramatic effect on your soil, plants, and overall health. Overfertilization is very common, however. Many farmers and lawn experts suggest using half a ton of manure or compost per 1-2 acres of grass to give back some of the depleted nutrients in the soil.
That’s definitely not what I would call “overdoing it!” Luckily, getting the right balance is mostly an educational process. There are many types of fertilizers with different ratios and amounts of each element.
You will want to make sure that you don’t run out of something before the next season. That could cause your plants to suffer from a lack of needed minerals.
There are also several free sources of natural fertilizer that we have mentioned along this article.
Too little can be bad for you
Having too few nutrients in your soil is not good, as this leaves your plants hungry for those needed vitamins. If there’s very little nitrogen in your soil, your plants will turn to taking up oxygen instead of consuming nitrates, which are found in many types of fertilizer.
This could result in poor growth or even death of the plant. Plants require adequate levels of both nitrogen and phosphorus to thrive and develop healthfully.
Too much manure-based fertilizers may also run out of water before they deplete, leaving the plant dry and starving it of essential moisture. This can sometimes cause the plant to drop its leaf tips, called drying out.
These symptoms usually show up when you notice thinner foliage or shorter hairs on the leaves. If you see these signs in the spring, try adding more mulch to the pot to help keep the roots warm and protected. In the fall, apply a thick layer of compost to aid in winterization of the plant.
How can I tell if I need to adjust my fertilizer levels?
A way to assess whether your fertilization needs are changing is by looking at the soil test results you have already done. If dried out soils indicate lower nutrient content, then you do not need as much nitrogen (enriched NPK or “complete” plant food) or phosphorous (determined through testing forphosphorus), for example.
If dry soil indicates higher nutrients, then you may want to up-dose slightly and see how that changes the growth of your plants before deciding if you should decrease it again.
Take a plant test
There are two main ways to determine how much fertilizer you need for your lawn. The first is by looking at the plants in your yard!
You can take some grass clippings, put them through a composting machine, and then measure what kind of soil you have left. Then, you can use that information to calculate how many pounds of each type of manure or synthetic fertiliser you should use per 1 000 square feet (or one acre) of turf.
This way is very helpful because you do not have to buy every possible kind of fertilizer just to make sure your grass will grow well. In fact, most people don’t even know what types of nutrients their lawn needs!
The second method is to go into a store with a large amount of grass and pick up a sample bag. You can either bring your own bag or look online for tips on which ones are best to get.
After getting all the ingredients, you can mix it together and see if the grass grows fast.