I highly appreciate your question. Yes, it is highly related to future agriculture. There is no doubt now that new formats of agriculture like hydroponics/ aeroponics, green houses etc are to extend a lot for feeding ever increasing populations. Urban agriculture in the houses will also be developing too much for the new generations. Open field agriculture, though, will not be restricted but it will have to lend large support from other formats. Fertigation will increase with developing and extending supporting agriculture formats. You have asked pertinent questions related to fertigation. Definitely, we expect high quality answers from learned scientists who have rich experience on the subject. Although, I am not among these intellectuals, let me share my views.   

* Comparatively long duration crops are well suited for fetigation because you have to apply many doses to complete full requirements of crops.

* Fertigation can be more effective in sandy soils with rapid drainage because leaching losses are expected to be very high (especially N) when high doses of fertilizer are applied directly to the soil. Fertigation may be helpful in this regard.

* The role of water quality is very important in fertigation. If the water is saline or sodic, the combination of salts and fertilizer could prove damaging for plants. If it is waste water, then we have to take extra care.

*  The question of reducing cost of fertigation I leave for friends working on this aspect.

* Combining microbial inoculation and fertigation is a complicated question and need supporting data to say something but I do not have that.

* You are right that micro nutrients were not used much through fertigation but I do not see any specific reason for that. Let us hear from others.

Fertigation, INM, Aerial applications and soil applications are full replacements of each other. Rather these are supporting each other. We have to select one according to packages of specifications and conditions where we are going to use these. Here is the examination of the researcher to make site specific recommendations for meeting requirements of plants needed to grow in which soil and climate. What is the quality of irrigation water? What is the monetary status of the farmer, whether he can afford initial high cost or not? There are so many questions like this.

Let us have share and contribution of the cream of researchers at the Research Gate how they discuss and deal with this important question. 

I highly appreciate your question. Yes, it is highly related to future agriculture. There is no doubt now that new formats of agriculture like hydroponics/ aeroponics, green houses etc are to extend a lot for feeding ever increasing populations. Urban agriculture in the houses will also be developing too much for the new generations. Open field agriculture, though, will not be restricted but it will have to lend large support from other formats. Fertigation will increase with developing and extending supporting agriculture formats. You have asked pertinent questions related to fertigation. Definitely, we expect high quality answers from learned scientists who have rich experience on the subject. Although, I am not among these intellectuals, let me share my views.   

* Comparatively long duration crops are well suited for fetigation because you have to apply many doses to complete full requirements of crops.

* Fertigation can be more effective in sandy soils with rapid drainage because leaching losses are expected to be very high (especially N) when high doses of fertilizer are applied directly to the soil. Fertigation may be helpful in this regard.

* The role of water quality is very important in fertigation. If the water is saline or sodic, the combination of salts and fertilizer could prove damaging for plants. If it is waste water, then we have to take extra care.

*  The question of reducing cost of fertigation I leave for friends working on this aspect.

* Combining microbial inoculation and fertigation is a complicated question and need supporting data to say something but I do not have that.

* You are right that micro nutrients were not used much through fertigation but I do not see any specific reason for that. Let us hear from others.

Fertigation, INM, Aerial applications and soil applications are full replacements of each other. Rather these are supporting each other. We have to select one according to packages of specifications and conditions where we are going to use these. Here is the examination of the researcher to make site specific recommendations for meeting requirements of plants needed to grow in which soil and climate. What is the quality of irrigation water? What is the monetary status of the farmer, whether he can afford initial high cost or not? There are so many questions like this.

Let us have share and contribution of the cream of researchers at the Research Gate how they discuss and deal with this important question. 

Thanks so much Dr Nazir for taking so much of pain and letting our other colleagues know with your rich experiences on the issue . Your solid comments will go along way in giving some splendid responses to some of the quarries so far remained un-discussed. I am equally eager to receive the excellent responses from my learned colleagues.  

Thank you for this topic values my colleague that all crops are fertilizing according to a specific program for the same crop, the soils differ in terms of their contents from the elements and organic matter and adopt efficient fertilization on the texture, can reduce fertilization costs by using Foliar according to its purpose, it can be used insemination using yeast or bacteria or even fungi, and there are special techniques that, micro-nutrients depends on the emergence of symptoms and lack of it is a case of therapeutic use.

Indeed both soil properties and quality of irrigation water affect the effectiveness of fertigation. Perennial crops are better responsive to fertigation compared to annual crops.

Hussein, we cant wait for deficiency symptoms to develop to apply micronutrients. Prophylactically we need to apply micronutrients as annual maintenance dose to arrest possible emergence of any micronutrient deficiency symptoms. can you please elaborate on special technique of microbe application in fertigation.

Sikha, these articles may help you find a technique for the purpose of fertilization microbial and I'm now working on the use of yeast in improving plant growth and the search was not completed so far did not need a special technique and you are in India you will serve fertilizer microbial ( bio fertilization)  which is found ready to have my knowledge.

 Irrigation and fertigation. Needed or necessary?

The course of the weather and climatic conditions indicate the need for irrigation, even in the years przekropnych or those where rainfall is higher than the average of multi-year.

Doing plants with shallow root system, a high density, we need to irrigate in times of drought. The wetted soil zone of intensively developing roots are taken from this area nutrients. In places where the soil is dry, downloading is significantly reduced.

Irrigation, dilute the concentration of macro and micronutrients contained in the soil solution, which allows plants to heavy downloading, the consequence of which is the loss of minerals from the zone. It is difficult to make up the ingredients just in the zone where it reaches the water. The only way is to administer mineral system nawodnieniowy.

Fertigation is a "necessary evil". Why evil?

Because this additional procedure, where you have to deal with are used better quality fertilizers, thus more expensive. Necessary, because we get used plants that in a certain zone growth of their roots is water and there are minerals. If you do not complement these components, the plants begin to react to a reduction in growth and yielding worse.

What systems of irrigation and fertigation are most effective?

Nawodnieniowy system must be matched to the capabilities of the farm, including Source flow and water quality. These factors determine whether we can invest in sprinklers, the system minizraszania or drip irrigation.

Sprinkler system requires an efficient source of water. It can be used not only for irrigation, but also protect crops from spring frosts (orchards). Irrigation makes it difficult to work in the orchard - we can not perform actions when it is running. Driving the causes rutting. This increases the risk of infection scab.

Mini-sprinklers give water under the crowns, they need efficient source of water. Minizraszanie is a great option especially for growers whose water has a high iron content.

Drip Hydration is one of the most widely used irrigation systems in the world. It allows saving water, especially on young plantations and especially in young orchards.

Fertigation with mini-sprinklers and drip irrigation - there are no problems with the precise administration of appropriate doses, while the irrigation system raises the question of whether we want our fertilizers were placed also in inter-belts?

Do you feel the microbes could prepare the predisposing soil microenvironment for better use efficiency of applied nutrients

Hussein very interesting PDFs and equally informative as well. The efforts such as this will surely ensure the application of fertilizers within the rhizosphere zone of plants well treated with microbes so that there is a better water as well  as nutrient-use-efficiency. However , it remains to be seen whether or not multiple inoculation is possible?.

Agnieszka , I appreciate your response . Microirrigation systems in form of over-head sprinklers or under crown sprinklers in frost free areas have not been so successful , simply on the basis of water economics. Drip hydration coupled with water soluble fertilizers has most remunerative and responsive on multiple fronts. Can you please throw some light , how can we use the commercial fertilizers as fertigation so that the cost of the fertigation is drastically reduced  , otherwise use of soluble fertilizers comes as a big handicap in the way of large scale adoption of fertigation .  

Barbara I agree with you in totality about the effectiveness of drip irrigation along with use of fertilizers. Yes, roots develop according to placement of drippers within the plant perimeter. How is the wetting zone harmonised uniformly exploiting the the whole rhizosphere zone of the plant  will surely give an added advantage with fertigation efficacy .

We are reading interesting answers and data. This brainstorming may continue for a few days and I hope that more intellectuals will be participating in this discussion. Thus, the objective of floating this question by Anoop Kumar will be achieved.

How the effect of  soil salinity is minimised under drip irrigation , and nutrients find much better environment to be absorbed by the plant roots . And while doing so,  if rhizosphere soil is mellowed with salt tolerant  bioinoculants including AMs , probably the inpact of fertigation can be accelerated , much to the benefit of both soil as well as plant health. Maintenance of soil moisture near field capacity neutralizes both specific ion effect and total salt stress as osmotic stress by facilitating the salts below effective root zone.  

Yes, Anoop I agree to your arguments. However, minimizing salts under drip irrigation is debatable. There are two aspects. Drip irrigation saves water, therefore less water to be applied and less net salt addition. On the other side, there is lesser leaching of salts and salts may accumulate just in the root zone which is rather shallow one in case of drip irrigation. Hence, ultimate fate will be decided by soil properties, water EC, climatic conditions, frequency and depth of irrigation and the crop itself.

Very right Dr Nazir , that's the reason , I have raised the issue about the soil properties , predominantly we should consider while deciding the intervention of fertigation . Dr Nazir and my other colleagues , whats your opinion,  do you feel,  if soil properties are favourable for  effective conventional flood/basin  irrigation ( Depending upon annuality or perenniality of the crop ) with good quality irrigation water , same set of soil properties probably hold the same promise with regard to fertigation as well.  Probably fertigation will turn out to be more effective if soil is biologically more alive.

What are the major soil properties considered important with regard to efficacy of fertigation include soil pH ,organic carbon, EC texture and possibly soil depth.

Coming back to water quality requirement for fertigation , forward osmosis desalinisation of brackish water for meeting water quality requirement for fertigation  by integrating nano-filtration is recommended according an excellent paper by Phuntsho   et al .2013 published in Journal of Membrane Science  ( 436:1-14).

Another excellent work of Prof Kafkafi to see , how soil and water quality affect the efficacy of fertigation published by International Fertilizer Industry Association ( PDF enclosed for further reading ) .

What are the factors that govern the partitioning of water requirement and nutrient requirement  across different growth stages of crop. How do you partition  both water ad nutrient requirement.

Most of horticulture crops suited for fertigation by drip irrigation, also, the the field crop when have center pivot can use fertigation, but fertigation doesn't mean stop soil preparation and add compost for soil to improve soil characteristics 

That's why there is a definite role of different soil properties which need to be monitored in order to ensure better efficacy of fertigation.  Liquid form of microbes can also be injected into the soil through irrigation.

Dr. Anoop, here is answer by Sikha Deka to your question that whether or not liquid microbes can be applied through fertigation. I agree to Abdraboo reply that fertigation is very well suited to the perennial crops. However, fertigation is not a complete replacement of other nutrient applying methods. 

Good point , you have raised Dr Deka . We discussed this issue very much in the beginning , liquid inoculants can be effectively administered into the rhizosphere zone of the plant , annual or perennial in nature. Regarding the very pertinent issue , what kind of soil properties , we are looking at while monitoring the efficacy of fertigation . probably , those soil parameters will remain the same what conventionally we use to define the nutrient band biological environment of the soil .

My point of contention is , don't you think , nutrient delivered into the rorot zone of the plant will undergo same kind of transformation, parallel to what we observe in case of conventional soil fertilization?.

Very well said Dr Nazir . Let me raise another  very pertinent issue  , whether or not we can supply total nutrient requirement of the crop through  fertigation including both macro-and micronutrients.  As Dr Nazir , you said , we cant supplement total fertilizer requirement through fertigation , what could be the next  better option . Don't you think , in that situation , intervention of other methods of nutrient delivery  will hamper , even the efficacy of fertigation. Why don't we have  any work on complete fertigation scheduling (requirement ) of any crop . I am not talking about the fertigation using hydroponics/aeroponics.

I do not think our goal should be the elimination of the root system by constant water and nutrient drip.

Stronger and more balanced plants will result when stress is allowed to permit the expansion of root systems and the plant defensive mechanisms are engaged. This will result in lower total use of water when it applied strategically and greater ability to tap both the drip system and the soil.

Soil will be the most cost effective nutrient source even when combined with drip systems just because refined soluble material is relatively expensive. When we seek 100 yield goals we will use 80% of the input for the last 20% it is better to seek a 80% goal and conserve on the total resources added to the system.

Since resources are always limited in some sense the targeting of 80% will greatly reduce inputs and allow for less investment need. Our input overuse in technified system can easily become part of the problems rather than the solution.

The irrigation system needs the type of design and maintenance that will allow its operation over multiple cycles which is good way to reduce the continuing cost of production. Since these systems clog the use of water filtration and the agents to clean the systems are imperative. Chemical and biological fouling is part and parcel of working with advanced irrigation system.

When soil are optimized the need for continuous addition of water is much reduced as well as issues related to overall greenhouse gas impacts. Since the biggest impact for greenhouse gases is usually Nitrogen fertilizer and pesticides the ability to curb these are important for dealing with those issues.

The absolute scarcity of clean fresh water is going to lead to more and more drip systems with advanced control features as water is the biggest overall limitation to World agriculture.

How do you feel typical fertigation different from hydroponics?  Whether hydroponics is successful in perennial crops. If so please forward some PDF.

Let me first respond to Dr Hepperly , who gave an excellent account of the whole issue . Ferigation , we are looking as an excellent option to not only save on water , but nutrients as well , where quality of water will dictate   the water-use-efficiency by the plant .  Even , saline water can be safely used through drip irrigation .

Dr Deka , hydroponics is another form of  fertigation . there are certain advantages and disadvantages with soil-less culture called hydroponics. Soil-less production of fruits( PDF enclosed ) and vegetables( PDF enclosed) is a huge success of recent past since it is possible to regulate the off-line and in-line balance of both nutrient as well as water . Kindly go through the enclosed literature to get better idea about the success of fertigtaion , especially in horticultural crops.

Cant we develop a INM soluble substrate as a composite mixture which could find its utility under fertigation and hydroponics since  lot organic acids, chelates etc. are already in practice to improve the plant response of hydroponics.

Very interesting issue has emerged.  A big yes. There is a strong possibility to develop  INM mixture well compatible with fertigation comprising water soluble fertilizers carrying chelates  plus humic acid or water extract of tea compost or vermiwash plus the liquid culture of microbes , all brought together would  surely act as a very effectively module . Infact the same can also be tried under hydroponics.  interestingly , under hydroponics  , there is hardly any serious attempt to try out the  liquid form of microbial cultures ? 

This will be a new field emerging in nutrient and water management.

Thanks Dr Nazir .  Very strong intervention of organics in form of water extracts of tea compost , vermicompost etc  is already in practice under soil-less culture , why cant we attempt such combination, which is compatible on many fronts.

Sir,

Many scientist have discussed well.  If soil quality is known, then we can decide nutrient feeding which is needed more. If soil is deficient in any particular nutrient we can include supply of more quantity but with same concentration.  Similarly, good quality water is required for mixing of nutrients and their availability. 

Well said Dr Rajakumar , and we all endorse your comments. The bigger question is soil quality parameter delineate very strictly as per crop type . And different  crops behave differently on the same soil type ?

Seed coating applications helps reduce such problems.

well said by Dr. Nazir Hussain

Features of soil and water quality for irrigation is important. But it is also necessary to take into account many other conditions: the intensity and duration of irrigation, fertigation repeatability, especially crops, watering time ... The answer should give professionals.

Good response Dr Barbara

Thanks Barbara. Drip irrigation has now taken a different dimension in not only where there is  irrigation surplus , but holds equally good promise in those areas where irrigation water is not in abundance . Fertigation in form of open field hydroponics , protected cultivation , variable rate application ( GPS-based application )  exploiting the spatial variability in  field , have now come of age and effective across soil and crops   . I agree with initial investment in building up the facility , but over the years , due to profitability , fertigation is developing very fast. Hope , all of you will be unanimous on this point .  

well, I have seen many good answers from experts. Prof I may deviate from your question and will apologize but i will share some new news about the emerging tech in agriculture.

Prof,

Now a days I have seen seen some news on nanotechnology, which is also emerging in agriculture sector.

http://www.azonano.com/article.aspx?ArticleID=3141

also there is a paper published which I will research it as I didn't found it in my archives.

Good point Husain you have added to discussion on  fertigation using nano size fertilizers . We have seen nano size application of fertilizers as such produces very good response , but since in fertigation , water soluble fertilizers are by and large used , using nano size might not be so encouraging .

On a strictly economic criteria basis drip irrigation can be justified on the return on investment. This is most apparent on crops with high potential return or depending and the time patience an investor farmer may have. Drip irrigation is first applied on high value crops.

 If used properly the more controlled application of critical water and nutrients could potentially avoid issues of over application as the input is put exactly where it does the most good and exactly at the right timing potentially.

As sensing technology increases the plant or soil monitor can basically be used to call for the exact need when and how it will be needed to optimize the response. In global terms fresh water is probably the single most constraining factor in our overall food production system. Bottomline is that water conservation and reuse is needed and will become more inevitable with time.

I believe based on the needs and concerns the movement toward irrigation and drip irrigation is pretty inevitable.

Drip technology will first be implemented by high technology advocates but small farmers can innovatively use this for their energy, environment and economics also.

The use of gravity fed bucket irrigation systems with a spigot drip line can ensure excellent results for small farmers trying to make a go on short land resources and using their own labor. Abundance for a family can be available on very small farm parcels when farmed intensively.  Better food in this small farmer economy is a key to better lives for this and future generations in many rural areas.

It is more complex that just adding water..... but water is a big just and water needs to used efficiently. Where there is water there is life.

I am thankful for your encouragement Prof.

Even in the areas that retain a soil cover, the reduction of vegetation typically results in the loss of the soil's ability to absorb substantial quantities typically results in the loss of the soil'a ability to absorb substantial quantities of water. The impact of raindrops on the loose soil tends to transfer fine clay particles into the tiniest soil spaces,sealing them and producing a surface that allows very little water penetration.Water absorption is greatly reduced, consequently runoff is increased, resulting in accelerated erosion rates. The gradual drying of the soil caused by its diminished ability to absorb water results in the further loss of vegetation, so that a cycle of progressive surface deterioration established.

sh.xhd.cn/toefl/tpo/562670.html

The name fertigation may be replaced by the word Chemigation. Any chemical that dissolves completely in irrigation water can be applied through the drip/ micro irrigation system. The contact pesticide/ micro nutrient designed to be applied on foliage need to be applied by spraying only. Any pesticide/ insecticide/ micro nutrient chemical to be applied by root feeding can be applied through drip/ micro irrigation system. 

I am attaching a note published recently in Green Farming for my views on fertgation.

The name fertigation may be replaced by the word Chemigation. Any chemical that dissolves completely in irrigation water can be applied through the drip/ micro irrigation system. The contact pesticide/ micro nutrient designed to be applied on foliage need to be applied by spraying only. Any pesticide/ insecticide/ micro nutrient chemical to be applied by root feeding can be applied through drip/ micro irrigation system. 

I am attaching a note published recently in Green Farming for my views on fertgation.

Dr Kumarasamy nice feedback . Can you please share your experiences , how exactly the quality of irrigation water affects the efficacy of fertigation/chemigation?.

Dear Doctor Anoop Kumar Srivastava, As you might expect our water quality is quite varied. Living in Illinois my water around the Chicago area came of an artesian well resource and it reflected the bedrock dolomitic limestone high in Calcium and Magnesium as well as many other minerals. There was a problem with residues of lime, iron and the like. Living in Pennsylvania the hard water had a residue of black Manganese dioxide. When living in Puerto Rico the water was extremely deficient in Magnesium but the plumbing shows high local Copper found on the porcelain around the water devices and sinks. In Hawaii I encountered high salinity in the irrigation water.

Bottomline is that we need to get water analysis to better understand all these potential issues and advantages in or water systems.

When the water resources are charged with minerals these can interfere with the nutrients and chemicals for promoting intensive agriculture as they can interfere with solubility. Hard water will make it more difficult to get and keep minerals in solution. Since only mineral in solution can be utilized by plants this is potentially a big deal. 

In working with these issues I came across a very interesting practice related to water. I did not originally that water in solution will arrange itself based on the partial charges of water molecule. These charge attractions causes the hydrogen positive polarity to align with negative pole of the oxygen in the molecule. These phenomenon is called bound water state. When this alignment is separated the water is called free water and the nature of the water becomes best able to dissolve and to reduce nutrient precipitation.

In bound water the electrostatic attraction can be overcome in the water when magnetic forces is applied to it in a right angle the force freeing the water by  separating the alignment and giving it greater ability to wet and dissolve and prevent precipitation of mineral deposits. This allows much less laundry detergent use and cleaner clothes.

I applied this system to saline water source and resolved issues with salinity in Hawaii. In Pennsylvania the system eliminated Manganese deposits. The need for more work on this will help people take better advantage of a very low cost non polluting amendment which can improve the solubility of nutrients and reduce fouling with is limiting in the operation of many systems such as water heaters but also the irrigation system depending on drip that fouling.

The magnetic force is generated by a wound electrical coil around the water pipe which pulses to promote the magnetic force field. A computerized control allows the right pulses for the application and minimal electricity is needed for the field generation. When I first discovered these they were called Triangular Wave Technologies but I imagine there are more than one provider of this.

Dr Hepperly very informative inputs. Such kind of variation in ionic composition of irrigation water is more or less a commonality  in many countries including India. There is absolutely no doubt whatsoever , drip irrigation acts  very well with saline water . It is equally heartening ot learn that nutrient- use-efficiency  can be improved manifolds using magnetized irrigation water due to higher ionization of different cations , their movement is accelerated . Such practices are frequently utilized in country like Israel to improve the efficacy of fertigation. But , my question is still half answered Dr Hepperly , how does the such variation in water quality affect the efficacy of fertigation in terms of both nutrient as well as water-use-efficiency considering the ionic composition of irrigation water , calcium dominant versusu aluminium dominant or  neutral pH water versus saline water , to name a few examples ?

Dr Anoop Srivastava, Pertinent to the discussion of water quality and the use of water in agricultural is the application of basic principle that only that which is freely soluble ions are immediately available for plant nutrition.

In that regard I will look to the critical issue of pH and the example of Phosphorus availability as case in point. Maximum Phosphorus availability is a function of insolubility of Phosphate when other ions are in solution. In order of pH the interfering effect is Iron, Aluminum Manganese Silicon (Silicate) and Calcium (Carbonate). These substance allow maximum availability of the Phosphate at a narrow pH range of 6.1 to 6.6. This is the pH I would target in an irrigation system use ideally.

Secondly while some crops can benefit from saline irrigation the general idea is to have the irrigation water at a conductivity of less than 2 not to experience issues which would hamper the system sustainability.

Getting back to pH the activity of agricultural chemistry is largely an issue in the alkaline environment because of hydrolysis which occurs under elevated pH. In fact an amendment quite common is the Indicate 5 color indicator which buffers and indicates that favorable water chemistry. Slightly acid is the best for these reactions also.

At alkaline chemistry the most common issue is the insolubility of Zn, Iron and Manganese which can be a complicating issue in the production system. Authors had mentioned that Sodium predominance is an issue on that leads to potential  pH, micronutrient and soil characteristics issues aside from a direct effect.

The presence of organic material in water will inactivate glyphosate. For the GMO farming system they would want to make sure any spray water would not have soil clay or organic matter in suspension.

While I would steer away of trying to include as much Sodium as my plants might tolerate In terms of water quality to improve issues like water use efficiency I would suggest the use of in line drip applications of  fulvic and humic acids and the programming of a level of plant watering interval that would favor plant root development by programmed stress. This approach is needed because once people have irrigation going over irrigation is a common problem and lack of these humic substances can curtail the rooting of plants which are needed to have the strongest plants which are more available to utilize soil resources.

In terms of water use efficiency practices which raise the early and conclusive colonization of plants with mycorrhizae would be the most effective and for vegetable plantings. This is done by adding planting start medium to favor conclusion colonization by mycorrhizal fungi. In relation to this a too high Phosphate availability is counteractive to mycorrhizae establishment.

When natural area soils was mixed with vermiculate perlite and then planted to mixed grasses and legumes a season of growth with provide a very health increase in the mycorrhizae which then can diluted into a planting medium for the establishment of plants such as tomatoes and eggplants. These conclusively colonized transplants withstand drought better because the colonized transplants are pre-inoculated and the mycorrhizal symbionts spreads in symphony with the plant root systems.

In terms of water quality the ability to have a silicate concentration of greater than 1 ppm will help all the defensive response of plants and silicon is known to improve water use efficiency substantially. This is particularly important for a plant like rice that has high need and use of Silicon.

Some ideas related to the water quality issues you brought up.

Very nice supplement Abhishek  as usual . your responses come so pertinent to any question , besides the literature search that you do  seem to be hallmark of an excellent researcher. Actually , we were looking forward towards the utility of fertigation in domesticating the conventionally used straight fertilizers  to be fitted into fertigation . an d, partly , we succeeded in our intention of debating on this issue.  Wishing to have have some more indepth discussion . 

I got so much interesting information during the observation of the ongoing debate. Thank you.

Thanks so much   Vladimir ,  it means , we succeeded in our discussion through friends like you . Extremely thankful for  your encouraging words. 

Water quality in terms of SAR and RSE has direct impact on efficacy of fertigation and there fore both NUE and WUE are adversely affected if water quality is not good. 

Design of experiments can offer light to these questions from a statistical point of view. This is tradition of biologists in Europe and America of many decades.