Depends on what kind of agriculture and what kind of tax. India has done away with taxation on agricultural produce. There can not be a general answer to this question. Depending on what one is talking about. If the agriculture in question is corporate agriculture, basically meant for markets and profit, then it may warrant taxation of some kind. On the other hand if the agriculture in question is primarily small farm based agriculture, either for market or for subsistence, then taxation should not be an option. However, all those pundits of agricultural sector should keep in mind the time honored principle of studying agriculture: never study agricultural sector in isolation. The sector should always be studied in the context of the entire economy consisting of other sectors and the state.
However, to comeback to the beginning, the doing away with agricultural taxation has not led to the rapid growth of the agricultural sector in India. On the contrary the crisis in the agriculture has only worsened. Not at all that taxation would have solved the problem, that agriculture at all has survived in India as sector since Independence in 1947 is because there was no taxation. Agricultural tax would have brought about the crisis much earlier.
So, please find your own answers from my above account of India.
Although larger percentage of developing countries' working population are engaged in agriculture, majority operates as subsistence farmers owning less 5 hectares of land holding. This is not to suggest that there aren't corporate farms that can be targeted for taxation, however they are limited for this purpose. Probably more investment in agriculture is needed now to push the sector to the frontier. Otherwise introducing tax on the current state of agriculture could have deteriorating impact on food security and sustainable livelihoods in developing countries.
I would suggest considering the effect graduated land taxes have had in reducing average farm size, increasing intensification, yield per hectare, total output and therefore tax base.
Our experience in Kenya conforms to most of the comments made by other contributors above. With the enactment of a new constitution in Kenya in 2010, the function of agriculture was devolved to the forty-seven County governments of the country. One of the first things that Governor Isaac Ruto of Bomet County did after being elected in 2013 was to remove the tax on tea that had been imposed on tea farmers by the national government. From the point of view of development this was clearly the right thing to do. Some Kenya counties, thinking to raise local revenue from farmers, began to levy taxes on the sale of chickens in markets, etc. thereby taxing the agricultural sector into deeper poverty than it already experiences.
At present the n-ational government, in collaboration with County governments, is stressing the importance of value chain addition in agriculture. This policy has the potential to increase consumption, thereby fostering greater productivity in the agricultural sector and creating possible avenues for taxation revenue, not on the farmer -the primary producer- , but in the later stages - processing, tranport and distribution - of the agricultural value chain..