In Tropics the challenge is to adapt the modes of production to the climatic variability, trying to reduce the risks and the vulnerability of the production systems. Also, it is necessary to minimize the negative impacts of agriculture on the environment, otherwise we would continue to increase the likelihood of adverse events (torrential rains, prolonged droughts, strong winds, etc.). There are still important challenges for the development of national policies that support and promote efficient and sustainable agricultural production. Besides, the identification of risk factors is a necessity for the development of indicators to assess the sustainability of agricultural systems.

The development of risk indicators allows anticipations of the impact of threats but must be accompanied by an efficient communication mechanism with a significant scope, so that producers can minimize losses from adverse events. However, the internal strategies of the production units must be robust, which must be based on the implementation of conservation techniques, diversification of production activities and technological adoption, but for this, it is necessary to strengthen agricultural services institutions.

The scenario becomes more complex and we must necessarily consider socioecological variables such as soil slope, history of claims, protected areas, gallery forests, type of tillage, food and contingency water, type of rural infrastructure, soil analysis, producer education, income level, accident rate, technology and, of course, climatic conditions. The analysis of these variables (social, economic and environmental), as a whole, can give us a profile of the vulnerability of the productive systems, so that the institutions of the sector can address the problems in alliance with the producers, to face this challenge of the 21st century with adaption and resilience strategies.

The major limitations for tropical agriculture are the fluctuations of water for plant production and the soil limitations. The vast majority of tropical soils especially in humid areas are suffering from acid soil infertility and low organic matter. The first step to addressing these issues is the liming to remove toxicities and the supplementation for deficiencies. The ability of soils to capture and exchange water is large dependent on soil organic matter. The improvement of soils for their organic level which has been depleted by their use can not only increase the productivity and quality of crops but also can counteract the growth of atmospheric greenhouse gases. The tropical environment is favorable for continual issues with pests, weeds, and diseases. The crop food animal system needs to aligned with utilizing biodiverse systems to avoid calamities from these issues. While pesticides and synthetic inputs have sustainability issues the use of systematic controls and natural biological materials should be favored.

Climate change and population pressure could be some of the challenges.

Kidanemariam Gebregziabher Paul Reed Hepperly Enrique Alejandro Sánchez-Galán I totally agree with your comments.

A. Onakomaiya has a key insight that unstable politics and I would add corruption are debilitating whenever they are found. These twin towers of evil are found all over but need to addressed where ever they are found. Unfortunately they are most common in the areas of most need. The societal changes that are needed are not merely technological but also have much to do with the human heart as well as the minds. Resources of a capital nature will not work if they are squandered.

Adekunle Onakomaiya

1. Dwindling natural resource base occasioned by overpopulation orchestrated by climate change phenomenon. Poor smart and precision agricultural practices.

2. Inconsistency and poor implementation of pro-climate policies that tend to build resilience of worst hit actors.

3. Endemic corruption and poor leadership

4. Poor funding of research and technology, poor R&D as well as poor commercialization of research outputs

Likita Tanko Thank you very much for your comment. What you mean by "Precision agricultural practices".

One of the biggest obstacles in our global agriculture is addressing the field variation such as pH, compaction, etc.

Fortunately with the ability to map out the fields we can address weak areas so the uniformly high quality and yield can be obtained.

The use of sensors and precision application can make this feasible and economical on large areas.

Sensors can include soil pH, organic matter, EC and others. I am including a yield map. The use of drones can pinpoint inputs to only where they are needed.

The challenges are exacerbated by pressure of pests, diseases, and weeds. In the snowy or low temperature periods in temperate countries, the climate itself does the control: The invading species do not develop and pests or diseases die. In a tropical region, meanwhile, the environment is conducive for them to be active most of the year. This puts a huge burden on crop protection technologies, because if they are not used correctly, there may be resistance to the active ingredients or chemical groups that are in use.

As already observed, the climate variables are fluctuating and changing from time to time. On the other hand, the oil fertility is declining over time due to suboptimal management of the soils of arable land. Therefore, climate change (especially of water scarcity) and declining soil productivity will be the most important challenges for tropical agriculture.