Efficient water and fertilizer use towards yield increases and mitigation of GHG by AIC Agro Instruments
By optimization through monitored agriculture we can raise yield, reduce pollution & GHGs, boost savings and conserve energy & labour.
Our proposal is to optimize the amount of irrigation and fertilizer inputs. This is done by irrigating as per the optimal water potential range of the crop being grown along with monitored fertilizer application.
It is established that agriculture is a major contributor to Green House Gases (GHGs) and several studies have found that the same decreases when soils are not flooded/ roots are not submerged. Further over-fertilization in soils makes available nutrients that are lost either to leaching or immobilized or broken down and additionally released as GHGs.
We propose that irrigation be propagated as directed by tensiometers - the simplest and most accurate irrigation indicator. A tensiometer allows us to know when a plant is no longer able to draw out moisture from the soil it is growing in. Each plant has an identifiable optimum soil water potential range at which yield is highest. As soil water potential is irrespective of soil type, the trigger value for irrigating a specific crop becomes universal.
For understanding fertilizer requirements, a soil water sample from the tensiometer can be instantly tested using simple soil test kits. This allows a farmer to take instant remedial action if required instead of waiting for lab results. Indicative soil tests are now upto 92% as accurate as lab results, and are achieved in a fraction of the time lab tests take.
By adopting practices described above, roots are aerated better and anaerobic decomposition is reduced. Further, less fertilizer is leached or denitrified. Reduced irrigation further effects a cost saving in terms of energy costs (fuel/ electricity) to pump irrigation water. The multiplier effect of several farmers moving to such efficient systems, stands to reduce our GHGs output and other leakages and losses. Optimum fertigation leads to hardier crops, higher yields and is capable of being automated. By reducing costs and leakages and increasing yield and output, more value is capable of being realized.
What actions do you propose?
In the last century agriculture has undergone a sea-change, and its impacts are being understood now. At its core is the practice of growing multiple crops required to feed an ever increasing population. To cultivate the same there has been a shift from rain fed agriculture to exploitative dependence on ground water. Less than 1% of all available water is ground water. Therefore it is important to be prudent about agricultural water usage.
How we use this water has an impact on resource losses and generation of GHGs. We are now aware that agriculture contributes to about 13% of global GHG emissions – second only to the energy industry. Agriculture presently uses more than 70% of all freshwater, in use by the human raceand we also know that less than 0.8% of all available water on the planet is the usable fresh water supply we have for all of us.
Our proposal is to use water only as much as required – i.e. Adoption of optimised irrigation. This proposal is scientifically valid and economically sustainable. To mitigate the wasteful techniques such as flood irrigation, that allows anaerobic decomposition and gives rise to GHGs, we recommend instrumentation driven monitored irrigation. The instrument of choice is the soil tensiometer, which accurately measures the water requirement in the root zone of a crop.
Tensiometer monitored irrigation has been propagated for over 70 years now and is still surprisingly underutilized with less than .01% of all farmer s using it. We are yet to find a more accurate, reliable and affordable instrument to understand and schedule irrigation events in the domain of agriculture.
The merit of this device lies in the fact that it indicates if the soil moisture condition is conducive for agriculture. This is identified by the fact that different soils may have differing moisture levels/ percentage (extensive variable) but soil suction values/ soil water potential values (intensive variable) are irrespective of the soil composition/ type.
To clarify, the soil suction required to grow a crop in sandy soil and that in clay soil is the same, however the volume of water required, to make the soil suction the same, will vary between the soil types.Soil suction forces are a direct measurement of the force with which the soil holds onto moisture – reflective of the force a plant has to exert to get the moisture in through its roots.
For decades we have tested soils to identify water content of a soil and not the physics behind water movement characteristics, which are the more relevant parameter. Now research is underway to better understand the relation between soil suction and redox potential – an indicator of the soil environment and the tendency of organic matter to break down into GHG’s.
The tensiometer can easily be paired with irrigation controllers for automating the irrigation process; Or for users with less resource, be used manually. By maintaining crops at optimum soil water potential, highest naturally possible yield may be obtained. Limited irrigation has a direct impact on the amounts of water being pumped which further has multiplier effects – leading to energy savings and lack of excess water prevents leaching and runoff events in which fertilizers and other soil nutrients are lost. The indirect energy losses are staggering and as proposed, rational use of water has a domino effect in reducing energy requirements in agriculture, fertilizer and pesticide manufacture and allied industries.
In terms of fertilizer use, soil nutrients are supplemented in the form of fertilizers and over fertilization is damaging and a loss.
It is a loss when the bacteria present in soil breaks down Nitrogen based fertilizers, through microbial processes of nitrification and denitrification, into N20 – a Green House Gas. Excess fertilizer – not taken up by crops is easily leached into the water table where it damages ecosystems by contaminating the aquifers and the damaging effects are visible in diseases such as Blue baby syndrome and creation of dead zones in the worlds water bodies. It is also a loss of value for the farmer who had spent money to buy and apply the same fertilizer. Agriculture accounts for 67% of all anthropogenic nitrous oxide emissions.
A farmer can now easily test the nutrient loads of the soil his crops grow in and allocate resource on a real time basis using affordable colorimetric soil test kits. Adoption of this proposal in conjunction with the use of Tensiometer, assists in reducing our impact on the environment while maximizing agricultural output.
The first physical action that we recommend is setup of ‘pilot stations’/ ‘technology demonstration stations’ to demonstrate the efficiency of the two solutions proposed. This pilot station should serve to demonstrate the benefits described earlier. It will be a technology demonstrator as well as a data collection endeavour to identify the optimum inputs for each crop variety.
In the not so developed parts of the world, education levels are found to be lower. More so in the non-urban areas. It is in such areas that the majority of the agrarian population resides. They have adopted technology without fully understanding the demerits that may arise by over harnessing resources available to us.
Distribution of such pilot technology demonstrators in such rural areas, is the decision of the state choosing to adopt optimization – however it should be done at a micro level – with a unit for every 100 square miles in rural areas – to allow for the local population to see, understand and compare their own water use patterns.
This pilot station exercise also allows to explore pairing the proposed devices/ techniques with existing infrastructure that farmers may be using, such as drip irrigation systems or sub surface emitters with valve control techniques and/ or gravity driven irrigation structures. The impact on climate change will be proportional to the rate at which this technique of cultivation is adopted and propagated in each micro-environment.
In areas with fragmented land holdings, local governments must work towards propagating consolidation through cooperative farming by economically incentivising such behaviour. Larger landholdings allow for mechanization and allow for better utilization of labour and infrastructure, along with strategic/ symbiotic crop growth in paired systems. Such progress is seldom possible with small land holdings. It is more feasible for an agglomerated land holding to install a robust technological solution, as opposed to small fragmented landholdings.
In terms of social actions required, this knowhow must percolate to farmers. Nations should be guided on this technology development and data sharing must be done by them to ensure progress. National and international research bodies are well placed to study the impact and provide further progressive guidance for individual geographies and micro-climates. With greater adoption of the described instrumentation and techniques, we will get more data on ideal irrigation management and fertilizer management for each individual crop, leading to more efficient systems and accurate advisories.
In many countries, agriculture is highly subsidized. In many places misplaced subsidies/policies lead to incorrect and wasteful usage patterns. Subsidies/ policies must be restructured and may be made contingent upon adoption of irrigation management and fertilizer management techniques being recommended. Extractive systems in use must be complemented with the control measures proposed to make agriculture more sustainable. Subsidizing progressive farmers who adopt such techniques - through revamped policy – incorporating this proposal - will then work as a reward mechanism – and shall encourage adoption.
Agricultural extension services providers would be the largest community that stands to influence and guide such endeavours. Educating them is the primary task in addition to having ground truthing stations/ pilot stations. Having technology application specialists in the form of extension agents is most vital to the efficacy of this plan and having a technology demonstrator in the form of “Pilot Stations” helps most farmers see, believe and understand before committing to new practices.
The same extension departments can be tasked to propagate and inspect adopters to allow for subsidies to be transferred. Extension agencies are also well placed to guide farmers on crop selection based on the availability of water and local micro climate. As many farmers do not understand optimal irrigation requirements, such state supported handholding will make existing systems more efficient. A national level coordination will further streamline the availability of agri-produce nationally without being detrimental to regional ecosystems.
Finally, countries must invest in education for better management of agricultural land through classes/ videos/ handbooks and have local support, in local languages available through extension agencies. Non efficient systems and their demerits must be explained to farmers along with the long term implications of the same. This educational endeavour is targeted at accelerating evolution in behaviour.
The 10 countries with the largest agricultural emissions in 2011 were (in descending order): China, Brazil, United States, India, Indonesia, Russian Federation, Democratic Republic of Congo, Argentina, Myanmar, and Pakistan. Together, these countries contributed 51 percent of global agricultural emissions.
Tensiometer manufacturers around the world, are already serving researchers and progressive farmers in these countries and are well placed to support farmers who are seek to upgrade to new practices – should local governments adopt the suggestions of this proposal.
Such an endeavour should allow technology to reach the farmer, evolve behaviour, educate, promote responsible agriculture, and mitigate losses and wastage while maximizing earnings and savings.
Video of product performance available at https://www.youtube.com/watch?v=gs6ciqIr3jo
Who will take these actions?
These actions are required to be spearheaded by a global body such as the FAO or the World Bank and vetted through their research institutions/ advisory bodies who are in a position to disseminate information to the governments across the world. The first platform that may be considered is the CGIAR institutions who are the holders of the mandate to promote international cooperative agricultural research.
The findings from CGIAR institutions should cascade to individual nations who further explore in their agriculture focussed institutions before recommending for commercial deployment.
In businesses, Tensiometer manufacturers such as AIC Agro Instruments, Irrometer Co, UMS GmbH, Soil Measurement Systems, Soilmoisture Equipment Corporation, who are amongst the leading tensiometer manufacturers in the world, are well placed to serve the farmers across the world. Together, they serve progressive farmers and scientific researchers in almost every country in the world.
In parallel, aid/ support organizations can be guided in the use/ benefits of the tensiometer & soil test kits. They can act as extension agents to reach out to the many more farmers.
Lastly there exists complementary service providers at the individual level (Drip Irrigation system retailersand fertilizer resellers) who will come on board should governments approve and provide a mandate towards inclusion of the described technology/ techniques.
Where will these actions be taken?
Action should be first taken at the CGIAR centers such as
Africa Rice Center, Bouaké, Côte d'Ivoire / Cotonou, Benin
International Center for Tropical Agriculture (CIAT) Cali, Colombia
International Center for Agricultural Research in the Dry Areas (ICARDA) Beirut, Lebanon
International Crops Research Institute for the Semi-Arid Tropics (ICRISAT) Hyderabad (Patancheru), India
International Institute of Tropical Agriculture (IITA) Ibadan, Nigeria
International Maize and Wheat Improvement Center (CIMMYT) El Batán, Mexico State, Mexico
International Potato Center (CIP) Lima, Peru
International Rice Research Institute (IRRI)Los Baños, Laguna, Philippines
International Water Management Institute (IWMI) Battaramulla, Sri Lanka
and then be percolated to national institutions/ agriculture departments. Thereafter our proposed methods can reach the grassroots through the extension efforts of the individual nations.
Countries in Asia and Africa should be the first to try to adopt the technology as these areas are more ground water use intensive and they host a larger population that stands to benefit from increase in yields.
How much will emissions be reduced or sequestered vs. business as usual levels?
Adoption of the techniques suggested, by farming populations is projected at 25% by 2020, 45% by 2030, 75% by 2040 and 95% by 2050, in sync with national level adoption, reinforced with reward mechanisms such as subsidies.
Should this play out we are looking at atleast 25% cutbacks in GHG emissions in the near future peaking to above 60% at maximum efficiency.
The result of this adoption should hold emissions at 115 gigaton of carbon dioxide equivalent per decade by 2020 in India alone and bring a steep decline in emissions with passage of each year.
This will bring an equilibrium to GHG outputs from agriculture and further sequestering of the additional loads can be made possible through other avenues such as afforestation, improvements in power generation and utilization, and changes in transport design.
What are other key benefits?
The first major advantage of tensiometer usage is the savings made by pumping lesser water out of the ground. This results in lesser pumping costs hence energy savings. Secondly, yield of crop is higher when grown at optimum soil water potential. Using lesser water helps conserve nutrients in the soil and prevents leaching or runoff losses. This further protects the ground water from pollution. Groundwater recharge is a slow phenomenon and proposed measures can stave off desertification and subsidence occurrences.
When used in parallel with drip irrigation systems, irrigation is micro controlled and is made available for only the crop. There are success stories in which weed growth was averted by controlled release of water and nutrients. This is a major labour saving.
Lastly, stress induced agriculture studies reflect that crops provide highest growth and output in a optimal soil water potential range. By maintaining it as such, higher yield and increased earnings can be achieved.
What are the proposal’s costs?
Cost per instrument for manually monitored irrigation using tensiometers on a levelled plot is US$ 100. On levelled farms with similar soil profile, the tensiometer instrument provides representative data for 10 acres around it. An instrument has a life of a minimum of 5 years in most circumstances.
Thus the cost of the proposed action, at its most simple level is US$ 2 per acre per year. A soil test kit with 2 tests each of pH, Nitrogen, Potassium & Phosphorus is available at US$ 10. 1 kit is appropriate for 1 crop being grown in a relatively homogeneous environment.
In most cases, it is observed that the costs incurred on account of power/ fuel or excess fertilizer that is applied, is many times more than the cost of either of the proposed techniques.
Hence projected costs per acre per crop cycle should not exceed US$ 12 for the proposed methodologies per acre. Automating such setups will have a higher cost, however, that too will be less than the savings that can be made and/or the income from the increase in yields possible.
There continue to remain extraneous variables – especially the weather, which can play foul despite the best efforts of the farmer. However, we learn from farmers using such instruments that crops cultivated with such precision are hardier and handle both biotic and abiotic stresses better than those grown without such monitoring.
A realistic timeline for our proposal to reach the farmer should be a span of four years. Research institutes may run trials and test the methodologies under various stress factors for various crops. 3 years presents adequate opportunity to reiterate experiments across varying crop seasons. This is adequate to ascertain optimum irrigation values and nutrient requirements for each and every crop under cultivation.
Pilots can start with immediate effect and fine-tuned with data emerging from the research studies and a clear action plan can be shared and be practicable amongst millions of farmers in about four years.
A measurable impact on water use efficiency & GHG emissions should be visible in the medium term- within the next 10 years, and a decline from present levels of GHGs within 15 years.
In the interim period efforts on reforestation should be stepped up to begin sequestering the GHGs already in existence.