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Module 1: Historical Perspectives of Agriculture

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Video 1: Nature of Modern Agriculture
Now, lets think what is happening in a piece of land.Now here say for example you are growing these crops here and you are exposing them.So, here you have a piece of land and through 3 different seasons by the way, in Indiansubcontinent we grow crops thrice in a year which we call as a kharif crop which is therainy season where the sowing will be happening by the end of July somewhere.In some places have slightly earlier depending on when the monsoon is arriving and this lastfor next 90 days to 120 days August, September, October, by November the harvest takes place.Then comes the next season which is called the rabi season which is the winter crop wherewe grow wheat.So, in the kharif season we grow the rice, paddy mostly across the country, then we havethe wheat crop which is during the cold months, winter months January, February, March andthen of course we harvest it.Then comes a spell across the country which is kind of a tri spell that is what is calledthe zaid or the summer crop.So, you have kharif, rabi and zaid, so which is around April, May, June that is the kindof where very few really grow crops which rather depend on vegetables during that time.And here you have the rainy season and this is the winter which is mostly dry in India.So, these are the 3 cropping seasons we follow mostly across the country.So now, here you have a piece of land some hectare or something and you are growing acrop say A in one season.Say for example in kharif if we are growing A, in the rabi you are growing B and say inthe zaid you are growing P and this cycle continues.So, if I see so this is somewhere from July to November, then you have from say Novemberor December to April or March somewhere around March or April.And here from April till June, so round the year if you see it we are growing crops, nowas we are continuously growing crop as I told you we are depleting the nutrients.So, now while you are depleting the nutrients we are applying fertilizers and the storyof fertilizer if I have to say, modern days agriculture, major ones which are used Nitrogen,Phosphorus, potash.And if you look at it, nitrogen the critical one, nitrogen is synthesized by an enzymecalled nitrogenase by the biological world.There is enormous amount of nitrogen in the year but we really cannot trap it varyingaside rhizobium or symbiotic microbes.We will talk later about it, they are the ones who can fix the nitrogen from the environmentand convert it into a nitrogenous compound, nitrogenous form which could be made availableby the plants.Now, that’s not really sufficient when we are talking about growing crops round theyear, so you have to add more nitrogen and historically the breakthrough happen in thevery early part of 1900.This is the time major breakthrough was Haber’s process which changed the concept of growingcrops, this is where we could synthesize different nitrogenous compounds.Haber process is a landmark discovery earlier part of 19th century Bosch and Haber process,that changed the way we do agriculture for last, almost now 100 years.We had sufficient number of sources to produce ammonia, urea the source of nitrogen followedby potash, phosphorus.So, these compounds in the form of salt now started to dominate the modern agriculturessince 1900, early part of 1900.Now these are manmade chemicals and they have a turnaround time do you know mix up withthe soil, you know get acclimatize with the soil.But of-course the plants are pulling them through but now think of it is think of asituation in the very first part of my lecture I told you that we need organic matter totrap these things.So, they could be slowly release, so while we were adding all these kinds of things manysoils in many parts of the world where not being sufficiently supported with organicmatter.And what happen is because of not supplementing sufficient amount of organic matter.These excess nitrogen or phosphorus or even potash is started going down the soil andtried to get mixed with the water table.And eventually they cut at the water table in such a way that the nearby rivers or pondsor the water bodies had excess nitrogen, excess phosphorus much higher than their tolerablelimits, that let to a lot of unnecessary growth, excess vegetative growth in the water bodies,thus creating a lack of oxygen situation.Apart from contaminating or polluting the water bodies which includes your ponds, rivers,streams.So, you realize that though we have no other option, we have to depend on all these.But how much an individual plant needed, are we using them in excess, that is a very bigquestion which is now being posed in front of agriculturist and plant biologist, arewe really putting way more.And this is where there is a question which is coming a concept which is evolving in thehorizon of futuristic agriculture called which I have mention what today in a different contextI am coming, precision agriculture.I told you the problem that we are applying these compounds in excess, you have to findout a way to reduce that excess, how we can do it, could we ensure say for example somewhereother, could we ensure suppose here I have a plant which is growing okay.These are the shoots and could I ensure that my required compound or chemical remain concentratedin this region or I do a foliar spray or somewhere other it works, so lesser concentration.Second thing what happen because of this kind of situation many of these plants startedto grow much more than their limits which eventually attracted more infestation fromthis part of the game, insecticide, insects and microbes.

Video 2: Challenges of Modern Agriculture
So, this leads to an excess use of insecticides and pesticides, now the problem of using excessinsecticide and pesticides is they become part of food chain.Because when you are putting them unless otherwise they are metabolized by the plant, they willremain either in the fruits or in the stem or in the leaf or in the roots and we consumeall of that.We consume the root of some plant, we consume the shoot of some plant, we consume the undergroundfruits of some plant, we consume the fruits of some plant, we consume the leafs of certainplants.So, unless otherwise the insecticides or pesticides or microbicides whatever you call it are thekind the plant is the ability to degrade it during its life’s span of mostly if thecrops are of like you know unless it is sugarcane which is 9 months or 10 months crop most ofthese grain crops are like you know 90 days to 120 days and so forth, unless they canmetabolize all these things degrade of these compounds they will remain within the plantsystem.And this is the serious concern for several hormonal disbalances, which affects the femalepopulation big time because of the complex hormonal milieu and of course mail too.So, there are several diseases which are because of the residues of these compounds which arefound in the full products.Similarly, if these are used for the fodder crops, a lot of it goes into the animal sideand which eventually becomes very interesting.Like if you think that you know there is always at the bait among the vegetarian and a non-vegetarian or the thing is that the whole gamete of agriculture.If it both of them equally, say for example there is a like example of a say fodder crop.Now a fodder is getting say some form of insecticide or fungicide or you know something, so nowthis is consumed by an animal, say cattle.Now we are deriving milk out of it say, so milk will have the residues of this travellingor you using it for say meat or even say eggs.So, these residues are travelling along unless otherwise the fodder metabolizes it or theanimal metabolizes it and most of these compounds are not so easy to metabolize.So, you whether you are a vegetable eater or you are a non- vegetarian or you are somethinglike this, only a milk and plant, no one is peered in this game.Third thing, when we talk about weedicide or herbicides, these weedicides or herbicidesare again having the same fate, same problem because they become part of the plant andwhich moves into animal and whereas they travel along, well the situation is not grim.It is just we have to realize what is that amount which is precisely we can put whichwe can tolerate or which will go away.If we do it in excess there are always possibilities that we may hit the wrong chord and eventuallywill have to solve other problems which are much more relevant to the medical world.Now if you look at it out here, so we talked about the challenges what is there with theinsecticide and pesticide, we talked about the challenges of having fertilizers.We talked about the challenges of weeds.Now think of this situation, because of peculation along of different compounds or chemicalsused in agriculture.We now land up with another problem which is clean water resource and agriculture cannotbe done without water.So, that is why you will see there is a section in this course where we talk about nanotechnologyin water purification, the world where we are continuously contaminatingthe water, because of these compounds needed to be clean.Because this is one resource which unless otherwise we were technology to convert seawater or saline water into fresh water.We have a finite resource of fresh water and you have to work with the fresh finite resourcefor generations to come unless otherwise we make breakthroughs in water purification whichis happening.But scaling up is equally slow like if you visit places like Israel they do tremendousamount of water purification.Because they do not have much resources they have to do it, similarly there are other placeswhere water is one of the most challenging community or even if you go to places likeyou know Bombay and other places where we have limited supply of water it’s not thatyou will get water all throughout the day.There is a rationing of water but that is just to, at this stage to counter or to ensureeverybody gets it.But that is not who as human race we are we have to find out technologies, we have tofind out ways to counter these kinds of challenges.So, that you know our generations to come have ample resources to think bigger stuffnot to depend on these simple things.So, on one hand we realize that we do not have an option, we cannot go back, we cannotput the clock back.We started as nomads will became, become nomads or you know we will burn piece of land I willmove onto the next one, those options are not there, those are impractical situations.Instead what we have to think is how precisely we can use these chemicals in agriculturewhich includes crop production, vegetable production, fruit production, fodder production,all the way to animal production, poultry, dairy, meat and even leather as a matter offact get ensuring the assisting resources like land, water, environment is being conserved,we use it but we replenish it with our scientific technical know how.