Biomimicry
for shaping future
Agriculture
Limitations
1. Multi layer buffer strips
Strengths and Opportunities
The main strength of the implementation of riparian buffer zones is the provision of many environmental services. Besides contributing to a better closed nutrient cycle and preventing water and nutrient runoff, the buffer strips improve bank stability, reduce peak flows, provide shading and cooling of the water, improve water quality in the stream and consequently, improve aquatic life. Furthermore, within the vegetation, biodiversity is being encouraged, in both aboveground and belowground communities. Biological pest and disease control for the crop species can be enhanced thanks to the species present in the strips. By harvesting part of the vegetation from the buffers and using it as mulch on the crop field, less external nutrient input is needed and the cycling of the nutrients is therefore improved. The harvested biomass can be used for direct consumption or biofuel production as well. Another strength of our design is that it can be applied on different spatial scales. Not only is it possible to create the buffer zones along fields bordering a river or big stream, but also at smaller scale along fields adjacent to small gullies or ditches. As suitable, indigenous species can be chosen dependent on the location, which makes the concept applicable in a wide range of regions.
Opportunities can also be found in the application of this concept in areas where no surface water streams are available. In those regions the concept can be applied using terrestrial indigenous species that still prevent nutrient runoff and partly leaching, and enhance water filtration. Furthermore, farmers can work together with environmental organisations for gathering information and facilitating the implementation. Both parties could benefit from this collaboration. Local farmers have the chance to provide valuable information on what species can be used, soil properties etc. A last opportunity when applying the concept on bigger scale is recreation. Allowing recreation in the buffer zones, can provide benefits for the farmer in terms of income and raise awareness of, and interest in agriculture at the recreants.
Weaknesses and Threats
A consequential drawback when applying multi layer buffer strips is the occurrence of competition between the species within the strip and the plant species that are used as crops. This kind of competition can be defined in terms of nutrient competition, where the strip-plants deprive the soil from the elements that are essential for the crop production. Also, nutrient and/or light competition may operate within the strip-plants, where different plant species are used. This can lead to reduction of plant growth, and consequently reduced efficiency of the buffer strips functioning . Additionally, the size of the strips is a crucial criterion. Large strips means a smaller field area devoted to the main crop and thus, having negative impact on the yield. Considering buffer strips as small and diverse habitats for plants and animals that also host productive plants, an important issue emerges: the feasibility of agricultural practices within the strips. Harvesting in a multi-species environment can become a time consuming and difficult practice, and therefore new techniques could be implemented. The plants that will be used in the buffer strips should be well adapted to this small area. The parts of the field which are neighbouring ditches are dominated by high soil-humidity and possibly high concentrations of heavy metals and other pollutants coming from the the agricultural field or upstream flows. Furthermore, the field borders are severely exposed to environmental conditions such as wind. Consequently, species tolerant to polluted soils and adapted to tough weather conditions should be chosen. Plants that have an underdeveloped root system and that are not sufficiently adapted to this special climate make buffer-strips less functional. An important threat in the implementation of the buffer strips is mainly farmers’ acceptance. Adding vegetation in the borders of a field requires a modification of the farming practices, good maintenance, and a part of a land to be sacrificed with a consequential production loss. The decreased crop production has impact on the farmers’ income and therefore additional measures are needed that can make the “buffer strip” scenario better accepted by the producers.
2. Filtration system
Strengths and Opportunities
The most groundbreaking feature of the filtration systems is the ability to recover extra nutrients that would otherwise contaminate natural ecosystems, and re-apply them on the field. This filtration system has the double goal of contributing to closing the cycle of nutrients, making the farmer less dependent on external input of fertilizers, and decreasing the risk of water pollution.
This system has the greatest potential in areas that do not present large altitudinal gradients, and thus where runoff is not as important as leaching. In that case, filtrating water from streams and from the groundwater is the most suitable options to recover nutrients.Once the environmental and monetary values of retrieving nutrients are recognised, financial opportunities can come from subsidies and investments aimed at promoting the implementation and use of the system.
Weaknesses and Threats
Limitations of this design include the need of a substantial investment on front that will be repaid in the following years. The system we present is fairly complicated and on top of the construction costs, transportation and installation also have to be considered.
The filtration system has the aim of improving the quality of the environment, but the ecological footprint related to the construction is expected to be significant, and the functioning of the system is going to be energetically costly.
From the design point of view, some important details still have to be refined, such as the possibility of including a bioreactor to convert ammonia to nitrates, and a storage tank for the heavy metals and pesticides that are retained. Additional expert knowledge is needed to further develop this technical side of the project. In this way, the efficiency of the system can be calculated and optimized.
A common threat to innovative systems is the risk of encountering social disapproval. Farmers may consider the short term efforts that have to be made (investments, implementation, possible yield reduction due to the width of the vegetation strips) more important than the mid and long term benefits already described. Thus, information campaigns accompanied by a pro-active communication efforts (listening to their opinions) should be made. Another possible threat is the skepticism of governmental agencies and/or investors towards the project, which translates into the lack of sufficient funding to develop such system.
