If chemistry and monoculture are not reduced, the agriculture is neither sustainable nor ecological. The reduction and abandonment of monocultures and chemicals in agriculture confirm the concept of ecology and sustainability. In other words, if one may not reduce anything (without developing natural ecosystem), then what is the difference with conventional farming?

Agree with my colleagues in their contention that unless synthetic chemistry is reduced and biological diversity increased the ability to have sustainable productive ecosystems and farming systems is hampered. The structure of the so called modern industrial agriculture system is based on eliminating biodiversity. Yet biological diversity is the foundation of ecosystem productivity and stability. Rather than eliminate this we need to re-examine our food systems so they are based on proven biological principals. In the early 1990's Tilman and his team looked at Minnesota prairie in 207 field plots their finding clearly show that as number of species of plants increase the productivity of these plots increased correspondingly. Moreover more diverse plots were the plots that recovered most rapidly in the case of droughts or wild fire. Ecological zones with higher species diversity are able to give more primary productivity and the sustainability of these are increased. Rather than focus our agriculture on synthetic inputs and monoculture we need to look to nature for a more vibrant efficient and sustainable food system. This approach is to eliminate toxic synthetic inputs which are anathema to this goal.

A reduction of chemistry and monoculture is an unavoidable imperative to preserve food systems into the 21st century and beyond because these two concepts (although apparently effective) are the outcome (together with tillage, irrigation, GMOs and Confined Animal Farming Operations-CAFOs) of an industrial worldview for agriculture, which remains sustained by non-renewable energy (oil and gas). This model has been predicated in the northern hemisphere as the successful manner to produce food however (despite the efforts of the agroindustry), it has become a losing cause for the environment, the management of resources and the economics of family farms. It is imperative (in my opinion) to scale down from this industrial model of modern agriculture so that food production may transition from being extractive to restorative and regenerative. A large body of knowledge is presently showing that organic, ecological farming can be as productive as industrial agriculture without extirpating farmers and their communities from the land, and while maintaining a much better balance between production and renewability of resources (soil, water, germplasm, economy, etc.), which are needed to continue farming in landscapes that become also more resilient through organic, or ecological approaches.

Mixed animal and cropping systems show the capacity to create closed cycles of nutrients which improve the productivity of both the animal and the cropping systems. Returning to this tried and true system will allow the healing of the land resource which has been so deteriorated from the industrialized monocultural system and associated CAFO's which are so threatening to not only our land but our water systems. Optimized mixed animal and cropping system will result in return to real food and our health should improve related to improved food system based on biology rather than chemical inputs. Plants are designed to feed animals and animals are designed to stimulate plants and of this should generate an improving optimized soil system that does abuse air, water or the energy and economics.

Let us promote sustainability in agriculture through ago-ecological approaches by integrating biological, permaculture, little synthetic inputs.

Yes reduce chemistry by growing crops in their suitable environments.

Of course monoculture must be reduced. Ecologically unsustainable monoculture is associated to a big social inequality in the fields. Production should be carried out by many, many small/medium producers investing in many cultures. So, a reduction in monoculture is only possible if integrating to a more fair social distribution of land proprieties. Regarding 'chemistry', it is a too vague and unespecific statement. For example, chemical adubation in some extent is essential if we want a greater productivity even in polycultures. Some pest controls can be done via 'natural' inseticides - that is, extracted and\or isolated from plants. But if by 'reducing chemistry' you mean 'reducing the use of synthetic poisons', of course, this must be a worldwide goal in agriculture technologies.

Si, debería reducirse. Puedo compartir que es un llamado a nivel mundial, donde se involucra no solo ingenieros, científicos e investigadores; también empresas compradoras o importadoras de alimentos y consumidores exigen alimentos de calidad y sanos; con limites de niveles de sustancias químicas en su composición; aplicándose las Buenas Prácticas Agrícolas en la producción primaria de productos agrícolas, iniciándose como un sistema voluntarios en los productores, pero las exigencias de los compradores y concumidores de alimentos impulsa a que la apliquen los productores las apliquen. En Cuba, el monocultivo estaba difundido fundamentalmente en áreas cañeras, arroceras, tabacaleras y frutales; actualmente en los instructivos técnicos y campañas de siembra, posteriormente al cultivo principal se planifica rotación de cultivos incorporando plantas leguminosas en esas rotaciones y en los frutales, que son cultivos permanente se pueden asociar mango-piña; aguacate-piña; aguacate-mango (en esta asociación he presenciado en fincas integrales de frutales no solo intercalados entre hilera sino también entre plantas) y cítricos-leguminosa, en este último caso se puede sembrar en las calles leguminosas frijol terciopelo (Mucuna pruriens) o Canavalia ensiformis, de esta forma controla las plantas arvenses y aporta nitrógeno, aprovechable para la nutrición de las plantas, contribuye a la conservación del suelo no compactación del suelo por maquinaria agrícola, además del aporte de materia orgánica al suelo; mejorando así su estructura; al aplicar esta práctica disminuye el costo de producción, se aprovecha la superficie del suelo; es importante que cada productor en la planificación de las actividades de su finca incluya un diagnóstico, es decir debe conocer la zona geográfica donde está ubicada su finca; topografía; análisis químico, físico del suelo; cultivos precedentes (si anteriormente se sembraba en ese lugar); pero es bueno conocer la historia del lugar; condiciones climatológica y posteriormente al diagnóstico el establecimiento del cultivo, el productor puede aprovechar siempre las plantas naturales del lugar. Planificando bien, la rotación de cultivos y la asociación de cultivos es posible alcanzar la sostenibilidad de la finca; estás prácticas favorece la biodiversidad, camino a un equilibrio biológico y por tanto, a la disminución o eliminación de aplicación de químico para el control insectos y fitopatógenos, favoreciendo también la economía y salud de los trabajadores y consumidores.

I often read about the importance of crop diversification, mixed cropping, and crop rotations while looking documents on sustainable agriculture.

Dear Sushil Thapa, Look at the Rodale Institute Farming System Trial it has a complete review of the almost 40 year comparison of organic and conventional cropping systems side by side in randomized replicated field trials. It explains the effects of cover crops rotation and tillage and the transition to organic production systems. Search using Rodale Institute Farming Systems Trial