I know that many people think that progress is necessarily incompatible with the preservation of the environment. I do not think so, I think we have time to pursue a sustainable development, which use technological advances to produce resources more efficient, clean and environmentally friendly way.

ecosystem bee

Introduction of beehives of bumblebees to improve the tomato pollination.

Currently I’m enrolled in the PhD program on Greenhouse Technology and Industrial and Environmental Engineering; this is a research program focused on intensive production. I chose it because soilless culture is possibly the most intensive culture system utilizing all the resources efficiently for maximizing yield of crops and the most intense form of agricultural production of greenhouse vegetables.


Lettuce baby leaf greenhouse.

In this way it is important to improve the sustainability of these systems because they are the future, as they can feed more people with the same amount of land.

The Food and Agriculture Organization of the United Nations (FAO) think similar. In their book Save and grow Cassava they say that in the long term, closed cycle, very intensive production systems will be increasingly common. They also point out that sustainable intensification requires:

  • Smarter irrigation technologies
  • Better precision
  • Farming practices that use ecosystem approaches to conserve resources.

set fruit

Intensive culture system: cherry tomatoes in coconut fiber.

FAO’s book is actually a policymaker’s guide to the sustainable intensification of smallholder crop production, but I thought that I might apply its philosophy to my work in soilless culture

In order to grow, agriculture must learn to save.

These are the some of the things I have been working on:

Local substrates: volcanic rock

To conserve resources and reduce the negative waste impacts on the environment from soilless culture we characterized a local sustainable substrate: volcanic rock.

  • This natural substrate comes from a nearby volcano, unlike coconut fiber which comes from remote India.
  • It does not need a lot of water and energy to produce. Unlike rock wool
  • In this study we agronomically evaluated volcanic rock in three vegetable crops (sweet pepper, tomato, and melon) in Almería University greenhouses.

quarry volcanic

Quarry in the center of an inactive volcano. There is more info about substrates here.

Plants can use very effectively some trace elements

Silicon is not considered to be an essential element, so it is not always present in nutrient solutions. In fact, its role in the metabolism of plants is not absolutely clear. However, silicon’s positive effects on plant nutrition and plant protection are well documented.

We carried out  an experiment with hydroponic lettuce, tomato, pepper, melon, and cucumber plants. We measured the thickness of the plant’s cuticle, which is the first line of plant`s defense) and its protection against grey mould disease.

It works; nutrient solution enrichment with silicon  enhances plant’s defenses, so less pesticide is needed.


The epidermis is specialized in plant defence [source]

Still a long way ahead in using beneficial organisms in the culture

Some organisms help to reduce the use of chemical fertilizers, water and pesticides using microbial inoculants. But they cannot exist without an ecological context. The ecosystem approach is well known among organic farmers. The culture is not only the plants and the farmer, but there are also insects, microorganisms and beneficial plants, and each of them plays a role in your crop.


The use of microbial inoculants, particularly arbuscular mycorrhizal fungi (AMF) have a great potential for sustainable crop management. However, one of the major challenges of beneficial microbes application in agriculture is the variability of the outcome according to environmental conditions. Thus, it is an important challenge to understand the behavior of the mycorrhizal symbiosis under different plant growing conditions. Understand that only in protected soilless culture we can have a major control of the environmental conditions.


Fungi arbusce (blue stains) inside tomato plant root.

What other non-understood things can help our crops?

Recently I have had the pleasure to work with two specialized groups. One from the Spanish National Research Council (CSIC), and another one from Netherlands Institute of Ecology (NIOO). We carried out some experiments to know how some environmental factors:

  • substrate
  • phosphorus amount
  • light quality
  • light intensity

We are still working on it, but some of them could affect the symbiotic relationships with organisms, plant defense and yield. I really believe that I am working to make a better future, and that our research will help people live better lives.

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