We all know that the creation of a quality compost, stable and with good aptitudes to nourish our crops, is in the vast majority of occasions, a matter of time and letting the organisms that transform it do their job. There are times when we do not have this stable, mature compost and we have to resort to other solutions. We propose a compost of 14-20 days.
Index
BASES OF THE QUICK COMPOSTING METHOD
The composting process is, for the most part, a compendium of biochemical processes (including aerobic fermentations) at variable temperatures depending on the evolution of the process. In a generic way, composting temperatures can reach a maximum of 65-70ºC, with the vast majority of organisms dying. This is when most of the microbial activity stops and temperatures drop. From this moment on, the pile cools down and goes on to the maturation process. These processes, in general, usually take months. So how can we speed up this process? Let’s see the bases to achieve it.
The rapid composting method was developed by the University of California, Berkeley with very satisfactory results. It is not a complex method. It does not require the addition of activators or unusual elements in a compost pile. It only requires more care and effort in certain aspects that we will mention later. Obviously it is not possible, without time, to obtain a mature compost, mulch, or similar, but we can have a young product that we can add on the surface so that it matures itself in the soil of the garden, together with the crops and at the same time providing nutrients from the first moment. If you remember the article on stability and quality of compostWe mentioned that a mature compost is not better than a young one. It all depends on the utility that you want to give each one.
The method starts from 3 principles:
BALANCE OF THE RAW MATERIAL. C / N RATIO
We already saw in its day, the importance of the C / N ratio of the matter to be composted. The ideal data is 30: 1 although this is only a data. The composting process admits variations in the relationship although this data is established as ideal. To do this, we must take great care of this relationship in the primary components of the composting process. Around this C / N ratio, we achieve the highest activity efficiency of the organisms that act in the process. Perhaps this is the most difficult point to achieve if you do not have the right instruments. In any case, we leave you some data on the C / N relationships of the most used materials.
| Element | C / N ratio |
|---|---|
| Food waste | 15/1 |
| Wood chunks or chips | 200-500/1 |
| Straw | 40-100/1 |
| Paper | 200/1 |
| Manure | 5-25/1 |
| Coffee residues | 20/1 |
| Fruit waste | 35/1 |
| freshly cut legumes | 20-25/1 |
| Autumn pruning branches | 30-80/1 |
| Humus | 10/1 |
| Sheets | 40-80/1 |
| Bird manure | 5-15/1 |
| Grass | 17/1 |
| Diary paper | 400/1 |
| Wheat straw | 100/1 |
SIZE HOMOGENEITY. RAW MATERIAL CRUSHING
When we have time, we usually add plant debris, pruning and other elements to compost, in very heterogeneous shapes and sizes. Actually, it is not necessary to do a previous work of shredding these when you have time for them to compost “at your own pace”. In the case of rapid composting, shredding and homogenization is essential for two reasons:
- When shredding, we multiply the contact surface of the material to be composted many times , achieving a considerable acceleration of the process.
- Homogeneity in the heap. In the slow and normal composting process, the materials are piled up progressively, in layers, so that the C / N ratios are not the same throughout the volume to be composted. By mixing all the crushed elements well, we achieve total homogeneity and the processes will be carried out on the entire pile equally and with greater speed.
In addition to the above, there are direct consequences on the distribution of air and humidity in the compost pile. As is logical, the distribution and content of air and humidity are also homogenized, making the process faster and more efficient.
TURNING FREQUENCY
The last of the 3 variables that make the composting process go from months to weeks is the frequency of the turns. Most of the reactions produced in the process are aerobic fermentations. As the name suggests, they need air to develop in order for them to come to fruition and turning is the way to oxygenate the heap . It is recommended to leave the compost pile for 2 to 3 days without moving until most of the processes have been activated and the temperature has risen. Once this time has passed, the turning frequency becomes every 2 days. It is true that it involves an extra effort on our part , but remember that it is the basis of the method to get compost in such a short time.
FINAL EVALUATION
The time it takes for compost to be available varies greatly. Keep in mind that we speak of 2 weeks if all the conditions of humidity, temperature, balance of raw material, aeration… they stay within what the method considers ideal. In most cases, controlling all the variables to perfection is complicated and the process will take a little longer. We have already seen how to evaluate whether a compost is formed or not. Use the scent, color and structure methods that we discussed a few days ago to make a quick evaluation of the final product.
ADVANTAGES AND DISADVANTAGES OF THIS COMPOSTING SYSTEM
NOTABLE ADVANTAGES:
- The first of all and most obvious, the speed with which we obtain compost for our crops.
- Less leaching of nutrients, derived from the speed of the process.
- Being a rapid “thermally violent” process, the viability of weed seeds present decreases.
DISADVANTAGES OF THE SYSTEM:
- It requires a more exhaustive control and more effort (turns).
- The amount of raw material to carry it out must be abundant and available at one time. A minimum of 1 m³ of compostable material is required.
- Getting the C / N ratio is not easy. (Requires experience and / or analytical methods).
- Possibility of shredding large quantities of the material to be composted (shredder for pruning remains)