Dr Girish Puri was previously a Principal Scientist at the Department of Soil Sciences, Jabalpur. He talks about his research on soil testing.
Please tell us about your background.
Yes, of course! I am a retired chief scientist and professor from the Agricultural University, Department of Soil Science. My area of interest mainly lies in soil testing and fertilizer recommendations. I used to hold a PI position in ICAR projects. I am dealing with soil testing and fertilizer recommendations for the last 38 years. I like other areas of agriculture as well. But my main area of interest has always been with soil fertility and plant nutrition .
Which University were you part of?
Jawaharlal Nehru Krishi Vishwa Vidhyalaya (JNKVV), located in Jabalpur. It was established in 1964. There were a host of Universities that came up under the USAID land-grant programme. , The first phase was in Pantnagar and the second phase was in Jabalpur, Bangalore – they are all affiliated to US universities like Illionis ,Iowa ,Ohio University .Many universities were set up taking advantage of this land grant pattern, at that time – Jabalpur, Bangalore, Hisaar, Ludhiana Agricultural University, etc. were set up during the 1960 – 1970 period.
Farmers in general do not seem to bother much about doing soil tests.
Soil testing is a very good concept – no doubt about that. But, farmers are not educated about all this. Moreover, there were green revolution programmes that came up in the past, which was a government policy that I am not going to comment on. During that time, subsidy and emphasis was given only on the Nitrogen portion, not on the Phosphorus and Potash. So, the farmers dumped all the nitrogen/Urea into the soil. This created an imbalance of nutrients in the soil and affected the soil health.
It is highly necessary that a balance is maintained in everything one does and this includes fertilization of the soil. Balanced fertilization is a huge component that leads to successful agricultural produce. So there should be awareness and education at all levels – officers, farmers, etc.
So, attaining balanced fertilization is one thing.
Soil testing, as a programme needs to be educated to the farmers as well. They should be told about its importance and why the need for balanced fertilization. If they do not know the importance and the benefits, this programme is never going to be pragmatic.
So, the second thing is about educating about soil testing and its benefits.
Another thing is about the capacity of the soil testing laboratories, we have in India. There are about 120 million land holdings in India. Ideally, we need at least 40 million laboratories so that all the soil testing can be carried out effectively. Soil must be tested at least once in 3 years. Honestly, in India, right now we do not have the capacity to test 120 million land holdings. This is a fact.
So, the third thing is about increasing the number of soil testing laboratories we have.
Then again the government and the timeliness that needs to be maintained. Timeliness is another great factor. Delivering the results to the farmers on time almost never happens. Nobody values time, mainly because of the inadequacies faced by the staff and their technical incompetence as well. Soil testing departments are currently under staffed. People who currently hold positions are not even Science graduates. This is something common across all States in India. This is another reason why we are failing and why we fail to see the desired result in the agricultural sector.
So, the last important thing is about working on resources such that results can be delivered in a timely manner.
What is the next step after the soil testing?
After the soil testing results are out, next comes the recommendation. To give recommendations, one must have technical knowledge.
We should query farmers on:
The crop(s) that gets cultivated on their land
The irrigation facilities they have
Their financial status
Their credit eligibility
Based on these facts only can one make pragmatic and effective recommendations based on the soil test results. Also, the support shouldn’t stop at recommendations. These recommendations should be followed by follow-up action. Recommendation are not up to the mark because 5-6 devices are there for fertilizer recommendation and it varies from State to State as well. 5-6 types of recommendations are there, in my point of view. Now, these recommendations are only for soil health.
Precision, another much-needed component, is not considered when some recommendations are made. In some recommendations, they don’t take care of the credit facilities of the farmers. So, the whole action becomes baseless. They recommend something and that is it. The attitude is to take your reports and do with it as you wish.
What good is a recommendation, if it cannot be implemented? We have a long way to go in terms of recommendation. Officers should put some thought into whether their recommendation will be of any help to the farmer or not.
Will you say that right now in Indian agriculture about 10% of farmers do soil testing?
The truth is that farmers don’t even believe in soil testing. They don’t have the time for all this. Before the onset of monsoon, the soil sample should be taken. To deliver the reports, it will take about one and half months. Farmers cannot wait that long. They need to start sowing by the last week of June or July. So, delay in delivering the results from soil testing laboratories leads to his belief that soil testing is of no use.
Then in October, it is time to harvest the crop. And in hardly 15 days in November, it is time for the next round of sowing.
So, there isn’t any time available to be wasted in the soil testing activities. So, he tends to believe in the conventional method of dumping whatever fertilizer is available into the soil.
This state of affairs must be disappointing for you after having spent a huge part of your tenure in this spectrum of agriculture and now to see this on the ground.
Definitely! The trader controls the whole business nowadays. Farmers trust the traders blindly. He will dump whatever the trader suggests because there is a financial understanding between the two of them. Hence, the traders’ words surpasses all scientific theories. This is a fact.
The farmer and the trader get together and supply the soil with all these fertilizers to keep pests away. But, they don’t even give a thought about the residue level that gets left behind. It gets absorbed into the food and affects the consumers’ health conditions. Their aim is to protect their yield, nothing beyond that.
If the limit for pesticides is 3ml, they will pour in 10ml, because a 3 ml bottle is not available in the market. The trader will trade them with a 50ml bottle and be generous enough to say that the farmer can pay later.
This is a vicious circle and is a huge demon in the agriculture industry.
Looking back, what are some of the highlights that you would like to talk about. What you consider as your achievements?
My major achievement is the soil test based fertilizer recommendation for specific yield target of cereal,oilseed ,pulses , some of horticultural crops – it has a superior edge over other recommendations and it will serve farmers in a better way in terms of soil health , economics and productivity of produce . Of course, it will serve well at the stakeholder, farmer levels only if there is some programme to up the capacity of the laboratories we have. I will not comment on the merits and demerits of other approaches. But, this approach is very scientific.
The plant absorbs the nutrients from the soil as well as the fertilizer. So, in the recommendation part, we consider the plant and the soil. We must generate the basic data.which encircles the nutrient requirement ( total uptake of nutrientin kg /quintal of grain ), the soil efficiency, the fertilizer efficiency and based on that, we calculate the fertilizer dosage for desired yield of crop.
We must generate the basic data. The uptake has a linear relationship with the yield. If the uptake of a nutrient is more, the yield will be more. The amount of nutrient that is produced equals the unit quintal of economic produce. It means 2.2kg nitrogen is needed to produce 1 quintal of wheat grain. In this process the yield is predictable within a certain range. So, if you aim at 40 quintal of wheat yield, the nutrient requirement will be around 88kg nitrogen.
Now, we need to consider the soil health. Let us suppose that the soil has about 200kg nitrogen. This does not mean that all 200 kg gets taken up by the plant. So then, the efficiency of the soil nutrient is 30% in case of wheat. This means 40kg of nutrients plants will absorb from the soil and rest we must supply the rest through fertilizers.
Fertilizer efficiency is also calculated based on soil and plant intake, which is 50%. Again, that comes to 55-40 kg. This is the equation as per meticulous research and we have compared it with other benefit cost issues.
We also we went for fertilizer demonstration in the cultivated field not less than 1 acre. We checked if could achieve the target crop as per our calculation. We were aiming at a precision of + or – 10% of the calculated value.
Another point to be noted is that these calculations consider climatic conditions as well.
The advantage here is that, we can select low, medium and high targets. Achieving low targets certifies you as a marginal farmer who doesn’t have the capacity to spend more money; similarly, for other income strata of farmers. That way it satisfies all types of farmers.
We also have accounted for parameters like nutrient content, percentage contribution of soil, percentage contribution of fertilizer, etc. We derive the equation, based on these parameters. This equation is promoted in the soil testing laboratory. From this equation, we can say blindly that if we spend 1 kg of fertilizer, the farmer will harvest x amount of crop. When we say fertilizer, it is combination of Nitrogen, Urea, Phosphorus and Potassium. More than 200 experiments have been done on about 16 crops. This is for the purely inorganic site.
Now, organic farming has also come into the picture. So, we must check how organic matter is contributing in terms of nitrogen, phosphorus etc for plants. This way we must check whether we have to cut down the dosage or not. The cultivator may or may not have the manure. If they have the manure, the soil testers will put up the manure sectors also into the report – curtail the overall dosage. If they don’t have the manure, then we will suggest as per the farmers’ target/financial condition.
We can also consider multiple cropping approach. For this, we must consider the cropping sequence here because the time span is very less. So, in such cases, farmers cannot go for soil testing repeatedly between crops. So, based on the initial soil test, soil testers can forecast the post-harvest soil test value for the proceeding crop.
For example, if the farmer has soya bean and wheat crops. Based on the soil test done for soya bean, there are values prescribed for the wheat farming as well, at one go. Again, this can be advised based on target.
But, we have so many issues in putting all this into practice. People are not trained in the sampling methodologies. Moreover, the procedures take a lot of time to deliver the results. So, we need to go for the electronic sensor system. That way the electronic sensor can certify these results. We can use the selective electrodes to check the various parameters. This will speed up the process. One can go to the fields and use the sensors and transfer the data through the software laser. This will have inbuilt data on all the crops. This data that is collected from the field will go through the analyser. The analyser, based on the instructions, keyed in will output results based on the type of crops selected. We had tried this a long time back. It was Calcutta University who tried it. Here the software will generate a report based on all the inputs. This software can also suggest crops that can grow on the land based on the live reports. Hence, the software reports type and amount of fertilizer to be used by the farmer. This is a quicker method.
Is this software currently available in India? Are there any labs doing it currently?
Yes, it is available.
Are the soil testing laboratories in India mostly run by the government or are they also run by is it run private sector?
It is run by the government. We have more than 1000 laboratories and it is run by the government.
Isn’t there any scope for someone in the private sector to run such a laboratory?
When you think of scope, I don’t think it is a profitable venture as of now. The government has tried to implement this program at the village and block level under the soil health scheme. It was also aimed at creating employment for the rural youth. They had a budget of Rs 5 L.
The main problem then is charging the labor. Government suggested Rs 38 per sample. I doubt how this laboratory can run it at a village level.
The cost of the sample should be Rs. 700 – Rs. 800/- for this venture to be profitable. That is the issue. Then, there are hurdles like building staff, training them, etc.
There are soil testing kits available in the market.
The soil testing kit only does half the work of the programme. It doesn’t have the capacity to prescribe balance fertilizers. It will only give you existing information of the soil health. It is like getting yourself checked. You get results on your Bilirubin level, Sugar level, HB etc. The pathologist can only give you test results. You need a doctor for recommendations, right?
The soil testing kit is like a pathologist. It is not equipped to give you recommendations. Government has recommended 400 soil testing kits. But this is the limitation.
We have done the scientific research. But the thing is we must go for extensive extension programme. The funds provided for the extension programmes is not enough and we should recruit people who can solely deliver the extension programme motives to the farmers. Moreover, we must take into consideration marginal farmers. They are more in number.
Currently, what are you doing?
I am doing consulting work. I have a small piece of land with me near Jabalpur.
Important and essential aspects of soil testing
TIME AND METHOD OF SOIL SAMPLING : april to may and October zig zag method to draw sample from 0-9 inches top soil for grain crops , for horticultural crops 0-45 cms and 45- 60 cms of soil sample should be drawn finally the composite soil samples should be used for chemical ,physical and biological analysis.
FREQUENCY OF SOIL TEST : once in three years
TIMELINESS IN ANALYSIS OF SOIL SAMPLES : one month i.e. from collection of soil sample to issue of soil health card .
SOIL TESTING MOBILE LAB/VAN AND ITS SUPERIOR EDGE OVER STATIC SOIL TESTING LAB
1. An analysis is onsite .
2. No need of sample transportation and so helps in cost reduction.
3. More than one dist /block/ area can be covered simultaneously
4. Sample degradation is avoided
5. staff of mobile labs can be used to create awareness about soil tests and benefits of fert. recommendations amongst farming community n stakeholder by using the appropriate IT based digital media .
6.Remote areas can be covered.
7. Results are accurate and comparable to static labs as the protocol for methods are essentially same.
8. Training to beneficiary vis a vis soil testing .
Cutting edge technology : Soil test based fertilizer recommendation for yield goal/ target yield/specific yield target. This is superior over other methods of fertilizer prescription in respect to the points
1. Efficient and balanced use of fertilizers according to soil fertility.
2.It ensures the achievement of desired yield target within 10% deviation under optimum management condition .
3. It offers wide choice of fixing appropriate yield target according to availability of financial resources with farmers .4. Suitable crp rotation can be adopted from point of view of relative availability of crops to utilize soil and fertilizer nutrient 4. It ensures maintenance of soil fertility at an appropriate levels of cropping system for sustainable crop production
a. In the soil testing programme the protocol of analysis must have room for the micronutrient and secondary nutrient (Calcium ,magnesium, sulphur ) and thereof so fertilizer recommendation .
b. Keeping in view of the economic importance of horticultural crops, plant analysis is an urgent need of an hours to adjudge the deficiency and sufficiency of nutrients . Therefore the plant analysis may be taken up of priority basis only for the perennial horticultural crops like citrus ,mango etc.
Contact Address :
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