Overall the world is producing surplus food. lets look at the wastages experienced by both developed and developing countries. In Africa post harvest losses are great and something needs to be done. in order to combat the POP such as fertilizers, lets try and utilize integrated soil fertility management practices in order to built and sustain soil fertility. How ever we also need to reliase that organic farming does result in pollution of the environment especially where slurry is used, and where the produce has to be moved long distances to reach the market. Emerging studies (Tuomisto et al., 2012) from Oxford University show that integrated farming practices (IFP) that utilise both convention and organic technologies are greener and higher yielding. 

Thanks to all of you for your valuable contribution .Overall the world is producing surplus food right now, no doubt about it . The population of the world in 2010 was about 700 Crore and if the same growth rate is maintained the population of the world will be doubled by the end of this century.so, if we produce in the same rate as we are doing today definitely we are going to face a serious problem of 'food shortage' in the coming days. More over injudicious application  of chemical inputs ( Chemical fertilizer etc.) in agriculture to maintain a balance with the ever growing population polluting our environment so seriously that our existence in the land of living is in front of a big question mark. So, the serious question right now is , what strategies should be adopted to maintain a balance between food production and the ever growing population of the world ,keeping our environment safe to confirm our existence in the land of living .I am interested in different alternative farming approaches/ strategies that can be adopted.Shepherd mentioned about Integrated Farming Practice as an option. I want more discussion in this matter.

with regards.

Hi Sharon

     Thanks for your contribution.

 With regards.

Manas, you got your figures wrong the population growth rate is not increasing it is decreasing and will soon (mid century) turn negative. This is happening for the first time in human history and will have significant effects on world economics as without a growing population maintaining the current growth model is difficult. For more info search UN population figures and data on urbanisation and women working which reduces TFR, total fertility rate, to 2 (meaning a negative growth rate)

People have already started realising the ill effects of fertiliers. Whether we provide nutrients through organics or inorganics, the plant takes them as ions only. The only option before us is to follow the following schedule to minimise the chemical usage in a collective mode.

year 1. 90% inorganic + 10% organic

year 2. 80:20

Year 3. 70:30

Year 4. 60: 40

Year 5: 50:50 this may be conyinued for 3-5 years 

therafter it should be 40:60, 30:70, 20:80, 10:90 and 0:100. 

In this way we may ensure food security too.

Just to add on the organic discussion

The overall problem with inorganic fertiliser is that they are very un-economic. Meaning the true cost for the fossil energy used to make them and the pollution of air, water and soil it causes are not included.

If the global economic system would include all external costs of in-organic the organic option (with has also costs but lower and  less negative outputs) would already be the natural choice in farming and more research would be commissioned to optimise the use including recycling nutrients.

The real question is not "Can organic feed the world?" in a world with a long-term negative growth rate it is rather

"How much longer can the world afford not using organic?". Because the pollution of air and water builds up slowly, but there is no escape (e.g. Nitrate can take 50 years to filter through soil until it slowly, slowly increases the concentration in drinking water). Currently those costs can be measured but they are conveniently deleted from any national or global accounting system. In addition, they are not added to the in-organic fertiliser at point of sale which require global political will to enforce the 'polluter pays principle' (sorry if I was using too much economic jargon).

Interesting discussion, thanks Manas. To the question if ecological farming can feed the world, I think there is enough evidence now to say: Yes, it can:

Ecological farming can produce as much food as industrial, especially where food is more needed (poorer regions of the world, where people live mostly from cultivating the land). Some evidence:

1) latest studies on how ‘good’ ecofarming (based on biodiversity and rotations) produces almost as much as industrial ag, without the costly inputs and damages to the environment. (same link shared above for one of the latest studies http://rspb.royalsocietypublishing.org/content/282/1799/20141396)

2) ecological farming is one of the “development tools” that lift people out of poverty and keep control of the food system with the local communities, not corporations (e.g. FAO, UNEP, IAASTD, de Schutter, Jules Pretty, etc, etc).

3) feeding the world is not about producing more food in some industrial regions, but about producing more food where is needed and using biodiversity and local resources, that avoid the ‘debt’ trap of industrial inputs. (e.g. Pablo Tittonell studies,see for example https://www.wageningenur.nl/en/show/Feeding-the-world-population-sustainably-and-efficiently-with-ecologically-intensive-agriculture.htm).

4) Ecological farming is also about smart food production and consumption: reduce excessive meat consumption in rich regions, reduce food waste and avoid diverting food for biofuels. (e.g. see for example: Cassidy, E. S., West, P. C., Gerber, J. S. & Foley, J. A. 2013. Redefining agricultural yields: from tonnes to people nourished per hectare. Environmental Research Letters, 8: 034015.).

On organic fertilisers sufficiency, Badgley et al 2008 did a (rough) calculation of legumes rotations being enough for Nitrogen, globally. For P and others nutrients, there should be enough with good incorporation of all organic wastes into farm soils (manures, compost, ecosanitation!) plus keeping good soil health (cover crops, rotations, etc). Many problem with P losses is erosion of the soil. It is now quite well established that organic fertilisation practices are key for avoiding soil degradation and maintaining good soil health, now and into the future (Mader et al 2002, Bommarco et al 2013). 

I hope this is of some help, let me know if you want more references. Cheers, Reyes

Bommarco, R., Kleijn, D. & Potts, S. G. 2013. Ecological intensification: harnessing ecosystem services for food security. Trends in Ecology & Evolution, 28: 230-238. http://www.sciencedirect.com/science/article/pii/S016953471200273X

Badgley, C., Moghtader, J., Quintero, E., Zakem, E., Chappell, M. J., Avilés-Vázquez, K., Samulon, A. & Perfecto, I. 2007. Organic agriculture and the global food supply. Renewable Agriculture and Food Systems, 22: 86-108.

Mäder, P., Fließbach, A., Dubois, D., Gunst, L., Fried, P. & Niggli, U. 2002. Soil Fertility and Biodiversity in Organic Farming. Science, 296: 1694-1697.

Yes it possible to substantiate a significant amount of chemical fertilizers with organic inputs.

Studies conducted in coastal Kenya showed that it is possible to substitute up to 50% of chemical fertilizer (especially nitrogenous fertilizer) with farmyard manure or green manure without causing any significant decline in maize yield. This form of Integrated Soil Fertility Management is useful for the coastal region of Kenya, where soils are sandy and have very low organic matter content.

I am also in agreement with Shepherd Musiyandaka. Much of the food insecurity arises from post-harvest losses, especially in the developing countries. This is brought about by poor storage of harvested crops, leading to substantial damage by storage pests. Thus, in as much as we need to increase yields thorough the provision of good nutrition for food crops, there is great need to minimize post-harvest losses.

Yes, it is possible to substantiate plant nutrients through organic sources; farmers need to apply the amount which is removed from the system. To make the food production system secure, addition to the soil is necessary through integrated plant nutrient supply system (IPNSS).

But some sewage sludge (an organic sorce) has got some metal and other dangerous wastes. It could afect the security of the food.

Yes, sewage- sludge may contain heavy metals. Hence, once should be very cautious and the organic sources must be tested for nutrient contents and pollutants before those are applied to soil. 

I believe you meant to say "substitute" rather than "substantiate". Actually you should turn your question around and ask if it is possible to maintain food security with the use of chemical inputs in place of organic inputs. In reading a recent article in a trade publication for agrichemical suppliers, I was amazed to learn that it is becoming necessary to apply lime to the inherently basic loess-derived chernozems or mollisols of the American Midwest, after years of excessive tillage, use of chemical nitrogen fertilizers, lack of perennial grasses (hay) in rotations, and other non-sustainable practices. They are still losing soil at excessive rates, and are degrading the soils that they have - this in one of the most productive agricultural areas of the world.

The article was actually in Crops and Soils magazine, American Society of Agronomy, Vol 48, Issue 1, Jan-Feb 2015, pp. 6-11, by Tanner Ehmke: Managing acidified soils on the Plains.

Thanks to all of you for your logical discussion full of knowledge and wisdom.

With regards.