Purple garlic aims at sustainability

As many of you already know, purple garlic is one of the social crops most important to our local economy. Purple garlic (and other varieties of garlic such as white and spring garlic) generates a lot of work and many companies and families base their economy on this crop. One of the jobs for which garlic requires a major dedication is irrigation, without the irrigation water it would not have purple garlic of such quality as that generated in the area of Las Pedroñeras.

As with all tasks in agriculture, irrigation is evolving towards a more efficient use of inputs with the aim of saving costs and being much more efficient in production and therefore being able to have a more positive balance at the end of the campaign. With this objective in mind, the irrigation technique for garlic is changing and we will now detail how it has changed in recent years.

Since many years, the method of irrigation for garlic has been by sprinkling and this evolved to the use of hose reels in the last decades. Hose reels allows the farmer to irrigate easily as it requires only one person and a tractor to change it over the whole field. One of the problems with this type of watering is that it is not very effective as water is falling on the same place for a short time, although it is a large amount which, in some cases, compact the soil or damage the plant. However, the most important problem with the hose reel or sprinkler is that it requires a large flow of water and therefore the irrigation system (motor and pump) has to be well dimensioned. If we show some generic numbers, a hose reel works at about 6 bar pressure and takes about 10 hours to roll up (about 350 meters). This quantity can irrigate about 1.7 hectares and it requires about 250,000 litres of water. In addition, as we mentioned before, the engine needs to work hard to get out the water of the well. If we move to the new drip irrigation techniques the change is really important.

Drip irrigation on purple garlic is gaining popularity and will undoubtedly be used more and more in the near future. We told with our friends Paco and Julián, they explain us some of the advantages of this new technique. Drip irrigation consists of placing a pipe with drippers every two furrows (distance between furrows 45 cm). These drippers are usually 50 cm apart (1.5 litre drippers can also be used at a distance of 30 cm) and about 11,000 metres of pipe per hectare is used. The drippers used are 3 litters per hour and usually work at a pressure of 2 bar. So you have a water consumption of 66,000 liters/hour. Paco is doing 2-hour watering and in this period he is watering 1.7 hectares. This type of irrigation is much more effective since the water penetrates the soil better, there is no evaporation and the garlic assimilates it much better. In addition, another great advantage is that it allows fertigation.

The system that is mounted on the garlic consists of a programmer that is responsible for distributing the water through all the pipes installed on the field (this is fixed at the beginning of the field). Every 2 hours, this programmer opens and closes the valves so that irrigation is controlled for the entire field. In addition, there is a cyclone that is responsible for removing the sand that may have the water so that the drippers are not clogged. This cyclone is also programmed to clean itself from time to time (e.g. every 1.5 hours it opens automatically for 7 seconds to eject the sand).

Therefore, if we compare one system with another, using horse reel we can irrigate 1.7 hectares in 10 hours spending 250,000 litters and with the drip irrigation system, we irrigate 1.7 hectares in 2 hours spending 130,000 liters of water. On top of that, diesel consumption is considerable since the engine works at much lower speeds or can even be done by solar panels.

As far as costs are concerned, both systems have an important cost since the hose reel is a big investment (around 20,000 euros) and the drip system also requires the acquisition of pipes, cyclone and programmer. Pipes can be disposable or reusable. The disposable ones (also called tapes) are easier to handle and cheaper (0.03 €/m) and the reusable ones can be used for 6 years although they are worse for installation and more expensive (0.09 €/m). Another problem with the use of tape is that it has a very small weight so if there is a lot of wind it can move tapes from the ground. In conclusion, installation must be carried out with care in order to achieve a steady setup.

Versión en español.

Olive grove. Crushing of pruning cuttings

As we commented in one of our post of last month, one of the tasks that we carried out in the olive grove over these last months has been the pruning, both on young olive trees and on those we have in full production. These pruning tasks on the olive trees in production are usually done every year, although one year we practice an aggressive pruning and the following year a much lighter pruning. This year we have not made a very aggressive pruning and therefore we have not gathered excessive amount of pruning cuttings. On the young olive trees we prune every year and the objective is very different, since its aim is to form the tree without removing too many leaves because you can't decompensate the relation leaf-root. On large olive trees, when pruning is done, we think it is best to cut with a chainsaw, so imagine the size of pruning cuttings that are usually generated.

In December we bought a second-hand iD-David crushing machine. The truth is that we had been looking for a crushing machine for months and we quite liked this one (iD-David is a very specialized Spanish company in machinery for woody crops). We bought it in Talleres Marsemar (Villarrobledo - Albacete) and we have used it a lot (both for crushing olive and almond tree pruning cuttings). We had a very good feeling when we worked with it. The crushing machine is the iD-David TD-SO and it requires a tractor of at least 120 HP as it needs power when starting... we use it with our Agrotron M600 (130 HP) and the tractor works really fine at 1,700 r.p.m. of engine and 490 r.p.m. of PTO...  the crushing machine suffers a lot when many wood cuttings come in, especially wood of almond.

The aim of crushing the branches is to be able to incorporate these pruning remains into the soil because the pieces of wood end up decomposing and being incorporated into the soil as organic matter. We think this could be a very good choice for the olive grove and almond trees. Moreover, in Andalusia, the crushing of branches has been done for many years and the results are very positive.

Versión en español.