“Complete fertilizer in the conventional garden” – The term (still) stands for a certain form of synthetically produced mineral fertilizer, which is why this article is about this and about natural alternatives.
Table of Contents
Composition of complete fertilizer
What a complete fertilizer contains is basically explained quickly:
- N = nitrogen
- P = Phosphor
- K = Potassium
- N, P, K are also referred to as core nutrients, the complete fertilizer as “compound fertilizer”
The first complete fertilizer was “Nitrophoska” from the company BASF (brought onto the market in 1927), today many complete fertilizers are offered in solid and liquid form. The way in which the core nutrients are distributed in the complete fertilizer is given in percentages. Typical commercial spellings for the packaging have been developed: (13/13/21) or 13-13-21, also “NPK 13/13/21” or “N 13 , P 13, K 21 “and similar spellings can occur. The statement is always the same: the fertilizer contains 13% nitrogen; 13% phosphorus and 21% potassium.
The complete fertilizer brought great advantages, especially after the Second World War: food production is often reduced to almost zero in times of war, all of the usual stocks are consumed, up to long-life dry products and cans. When the war is over and the normal economy starts up again, the people must first be fed directly and, above all, from the fields, until everything else is replenished, it takes a while.
Every soil in which a harvest grows every season also needs every season replenishment of the core nutrients, which the crop consumes most during growth. Sustainable tillage with crop rotation, catch crops and green manure, which can be fertilized directly with residues from other production processes, is no longer possible if the farms in the area have been destroyed by the war. In addition, plant cultivation of this kind requires specialists, while artificial fertilizers could be used by anyone in any soil – and this is exactly what happened during the war and in the post-war period, so there were good reasons that artificial fertilizers were initially used in fields and in allotments. How useful it is to use complete fertilizers in the home garden today is very controversial.
Use complete fertilizer
Determine the different garden areas to be fertilized:
- When fertilizing a garden, all kinds of plants have to be taken care of
- Every plant has special needs
- So a garden consists of different numbers and sizes of areas with different needs
- In the case of complete fertilizers that work quickly and intensively, each of these areas must be fertilized separately
Determine the required amount of fertilizer for each area with specific fertilizer requirements:
- Complete fertilizer should keep the soil fertile, i.e. in a composition in which plants can grow
- To do this, it supplies the soil with the core nutrients that plants need
- When so much has been withdrawn from the soil that plants can no longer grow without being replenished
- This point in time is reached at different speeds
- Very quickly when fruits and vegetables are grown and harvested in the same season
- Less quickly if short-lived ornamental plants are cultivated and replaced soon
- Rather slowly, if there are long-lived native plants in the garden
- Almost never on areas overgrown by native herbaceous plants with the lowest nutrient requirements
- The time frame is usually recorded in a schedule
- In which the fertilizer requirements of the individual areas are entered
- For areas with alternating planting, the plan must be updated every season
Measure the amount of fertilizer, prepare the fertilizer for application
The use of artificial complete fertilizers only brings the desired result under certain conditions:
- In nature, the plant uses a wide variety of natural substances, sometimes in small quantities
- Complete fertilizer is highly concentrated and must be precisely dosed if it is not to harm the plant or the environment
- This is why complete fertilizer is always mixed for a certain area known in square meters
- Instructions on how to best measure the desired amount of fertilizer can usually be found on the packaging
- And how the highly concentrated fertilizer is distributed in such a way that the planned quantities reach the plants
When the plan is in place, what is to be applied where and in what amount, the next step is to provide the fertilizer:
- Pour fertilizer in the desired dilution into the container from which it is to be applied
- Some gardeners prefer to fertilize the areas with different needs one after the other
- Some gardeners place several fertilizer containers next to each other and proceed methodically
Applying complete fertilizer
Even that is not even possible “just like that” with highly concentrated complete fertilizers, but should be done (also to protect the plants) under the following favorable conditions:
- Never apply in the blazing midday sun, but as early as possible in the morning or in the late afternoon / evening
- Never fertilize on dry soil, but on slightly damp or previously lightly watered soil
If everything fits, you can start, now you just need a lot of concentration:
- In the case of highly concentrated fertilizers, even distribution is necessary and uneven distribution can be harmful
- If possible, do not apply fertilizer directly to the leaves (if foliar fertilization is not the goal)
Fertilizing with complete fertilizer only makes sense after a soil analysis
If complete fertilizer is to be dosed precisely, this raises the question of how the “exactly right” dose can / should be determined. Unfortunately, the package only apparently provides instructions for this. On the fertilizer packs that have been packed for the hobby sector, certain application rates determined for average requirements are indicated, which may or may not be suitable for your garden and your plants.
The hobby gardeners who buy directly from specialist companies without going through corporations (which quite a few hobby gardeners do because they don’t feel like paying a much higher price per kilo for repackaging in small, colorful plastic packaging) know it: on the fertilizer sacks, which are also sold to professionals are sold, there is no more than: “The application rates depend on the crop requirements and take into account the nutrient content in the soil. Do not dose excessively. “.
The professional knows the crop requirements (whereby, like the successful hobby gardener, he draws on a mixture of knowledge and experience) and takes into account the nutrient content in the soil by having a soil analysis carried out at regular intervals. The hobby gardener would have to do the same, because the fast-acting complete fertilizer can hardly be applied sensibly without a soil analysis – but it does so in very few cases, which is why overfertilization is regularly found in the home and allotment garden area and many lawns are in colorful dandelion meadows that show over-fertilization with nitrogen.
This is why hobby gardeners who want to use complete fertilizer can do well if they have a soil analysis carried out every few years. The standard soil analysis determines the supply of the soil with the main nutrients and mostly also the most important trace elements, humus content / nitrogen supply. The nitrogen content cannot be examined very precisely, which is why the use of a quick nitrate test is recommended, especially before sowing “hungry plants”, which determines the mineral nitrogen content (can be bought with instructions for using the nitrate test strips).
Once the initial values have been determined and used for fertilization, there is usually no risk that the values will change quickly and dramatically, which is why a review is only due every few years. The local environmental authorities usually have addresses ready where soil analyzes are available nearby and cheaply.
Advantages and disadvantages of complete fertilizers
The advantages of the complete fertilizer are high concentration of nutrients in a small space and good storability, the fertilizer package does not weigh much and is easy to transport. The advantage of the high concentration often has a rather negative effect in the home garden: Regular nationwide soil surveys also regularly show that home and allotment gardens are not optimally supplied with nutrients. At the moment over-fertilization is more the rule; Since this fact has been the subject of more and more media attention recently, one can probably wait to see when “the fasting wave will break out” in the conventionally fertilized German garden.
The explanations already show the first disadvantages of fertilizing with the usual complete fertilizer, especially in the home garden. A typical complete fertilizer range from a supplier looks like B. looks like this:
- NPK fertilizer 12 + 7 + 17 (+ 2 + 8)
- NPK fertilizer 12 + 12 + 17 (+ 2 + 8) + 0.05% Fe, 0.02% B, 0.01% Zn
- NPK fertilizer 13 + 7 + 16 (+ 2 + 6)
- NPK fertilizer 13 + 9 + 16 (+ 4 + 7)
- Entec perfect 14 + 7 + 17 (+ 2 + 11)
- Nitroperfekt 15+5+20 (+2+8)
- NPK fertilizer 15 + 6 + 13 (+ 3 + 5)
- NPK fertilizer 15 + 15 + 15 (+2)
- NPK fertilizer 16 + 12 + 8 (+ 2 + 5)
- NPK fertilizer 16 + 16 + 8 (+4)
- (+ 2 + 8) stands for 2% magnesium + 8% sulfur, + 0.05% Fe, 0.02% B, 0.01% Zn for small parts of iron, boron, zinc
So there are noticeably many different complete fertilizers on offer, which differ in their percentages. Manufacturers only do such an elaborate mixing process when it makes sense – the only slightly varying percentages are therefore a good indication of how finely you have to choose in order to satisfy a particular plant in a particular soil. And when you have selected the right ratio of nutrients to each other, the math only really starts if you don’t want to fertilize “by feeling” (the variant that is often practiced, but is often not really beneficial for plants, the garden and the environment).
Is comprehensive plant supply possible with synthetic complete fertilizers?
Let’s say yes and no, or it depends on what the gardener is aiming for: If a beautiful green garden is enough, in which the plants grow splendidly, but also occasionally have to give up and replace with too much or too little fertilizer, you can go under Use of complete fertilizer will achieve satisfactory results. Passionate mathematicians who are happy to calculate the most varied amounts of fertilizer for a wide variety of garden areas every year can even achieve a perfect basic garden supply with complete fertilizer.
However, the complete fertilizer does not provide the plants with the complete nutritional program – similar to how humans can not only live on protein, fat, carbohydrates, but also have to supply the body with around 40 other substances, some daily, some at regular intervals and overall from a colorful and varied as possible Nutrition benefits best, plants do not only get by with the core nutrients in the complete fertilizer, at least in the long run.
Even if (as is the case with humans) it is far from being fully researched what plants need besides NPK, one thing is certain: Nitrogen, phosphorus and potassium are initially not available for plants, which is why they are in the complete fertilizer. Plants also need sulfur, calcium and magnesium as core elements; Iron, manganese, zinc, copper, chlorine, boron, molybdenum as essential trace elements, beyond that one is still researching. It can be assumed that plants utilize many other elements in nature, of which we do not know whether they are necessary or only useful. The plants need all of this in more or less large quantities, which (at least in theory) can be made available through commercial supplements to the complete fertilizer.
In practice, an exact calculation of the amount of all these “nutritional supplements for plants” is hardly conceivable for the home gardener – rather, with so many different elements, the effects of which also have to be coordinated, it is more of a task for the computer center of a university. Whoever wants to garden properly (not with the plants that everyone has or that are currently in trend, but with the plants that he himself has selected for certain purposes, wants to eat parts of these plants himself and for other parts wants the plants to be important as old as possible), therefore usually grows beyond the complete fertilizer over time. Or rather, it grows beyond artificial mineral fertilizers, because its somewhat appropriate use appears to be more and more disproportionate in terms of the amount of work involved,
Trendy alternative: fertilize naturally
Fertilizing is supposed to provide the plant with the necessary nutrients. In the wild there is no fertilization, organic waste rots there, and the nutrients contained in these residues are returned to the plant via sometimes very complicated mechanisms. So nature regulates the fertilization itself quite well, and many home gardeners are now realizing that it is to their own advantage to leave the garden to nature to the extent that it can do the fertilizing thing itself again.
Because when millions of biological helpers fertilize, fertilizing works much better; without complicated calculations, without pesticides for weak plants that have grown too quickly, without dangers for the groundwater, without “fertilizer taste” in the salad. And also completely without a complicated conversion to natural garden: The remaining complete fertilizer is used up and gradually replaced by organic fertilizer.
Initially maybe with organic fertilizers from the pack, e.g. B. Cuxin Orgasan Organic complete fertilizer, which gradually lasts longer and longer, because compost has long since matured and gardeners who are keen to experiment will also discover with a lot of fun what else can be disposed of as fertilizer in the garden: nettles and many other (un) herbs and plant residues give the garden soil structure and nutrients when rotting, the water used from the freshwater aquarium contains plenty of potassium and nitrogen, dried yeast, banana peel, residues of beer and cola (for Plants healthier than for us), eggshells, egg and vegetable boiling water, hair, wood ash, coffee grounds, milk, mineral water, tea leaves and all withered flowers and vegetables contribute nutrients.
Conclusion
Complete fertilizer does not necessarily supply the plants optimally and is no longer necessarily “hip” in the home garden, also for ecological reasons. Whether professional home gardeners can dare to experiment gradually to incorporate more organic or “completely natural” (in the sense of household waste, just “fertilizing molecules in a natural compound”) fertilizer into their plant and soil supply ultimately depends on nothing other than personal Interest in the matter. If there is a little time and head free for this, experience has shown that the changeover brings personal gain and makes work easier for the gardener.