Nice question ...off course what you said is 100% true..

I think , application of 4R Steward principles is direly needed . Right quantity , at right time at right crop stage in right form..... if at all , if have draw maximum use efficiency of any aplied input.

Right time would be according to plant needs.

This changes at different crops and stages.

the losses of nutrients come from water loxxes and volatilization.

Getting the nutrient into the solution and near site of absorption is very possible with subsurface dirp irritation using fertigation.

If the ammonated material is not not put in soil contact the volatilization will be high.

All of this also needs to be done economically.

nice to hear

Decision making based on 4R (Right time, Right dose, Right place & Right source) is a toughest job. It needs a lot of analytics (crop & soil) and thinking

Then , please suggest some practical but scientific method of decision making synonymous to 4R principles.....unless one is expertised in decision making analytics, i doubt , one can really manage the crop scientifically . Lets not guess anything ....while doing so

Sempre é importante ter em mente que o aporte de produtos, insumos e mão-de-obra deve ser criterioso, técnico e econômico.

Ainda mais na agricultura orgânica, onde justamente, tem o objetivo de diminuir pegada ecoógica, produzir de maneira sustentável.

Sim devemos aplicar os insumos no momento ideal, na dosagem correta, na sequencia certa e otimizar as ações.

Anoop Kumar Srivastava currently, only books, chapters, and papers are on peak but we need practical knowledge that actually does some changes. Here, is vice versa.

waste can be used in many ways and one of them is for farming. In fact it is more efficient

Mª Angeles Zorrilla Lopez-Perea In what sense? Can you please eloborate?

Yes , 100 % ...not only at right time but also at right amount and at right place (management of temporal and spatial variability related with nutrients in the soil... actually this type of practice is the basis of the precision agriculture that application of nutrients to the plant or soil when it requires...if we go beyond the critical period of application of inputs (water, fertilizers and pesticides) , there will not be utilisation by the crop plant but losses and extra cost will be incurred...

It is very general saying that "Everything can wait, but not the agriculture"..

Appreciating the good response from Hminashu , let me add my bit over what i added previously. Aqarab Husnain , i agree only partially with you . 4R should be considered asa capsule for any package of practices , these 4Rs are applicable to even pests and disease management , so lets concnetrate on 4R for nutrients for example....

Right amount of fertilizers: We simply keep applying RDF called recomemnded doses of fertilizers years after year without considering the leftover/unused fertilizers ( residual fertilizers ) , is it necessary to apply fertilizers at such indiscriminate rate with bringing a concept of NUTRIENT HOLIDAY , means identify the year where you dont equir eany fertilizer application and , thereby , adjust the doses of fertilizers and dont apply thise nutrients which are in optimum quantity in your soil on agiven year. this will reduce the cost of production . This is the practical application of first R.

Right form of fertilzers : Why should you apply any fertilizer in your soil , without considering the soil pH and other soil properties. Why should i apply ammonium sulphate having acidic residual effect in our acidic soil and vice-versa , the practical application of second R.

Right stage of application : We infact need to know , when is what nutrients needed , accordingly we have to tailor the nutrient application in order to maximise the crop production . this issue , Himnashu also touched quite well. this is inafct the basis of precison agriculture ensuring nutrien-t and water-use-efficiency , with economised cost of production .In the past , such information was direly missing . This also laid the very foundation of fertigation in both cereal as well horticultral crops , fruit crops being the biggest beneficiary. with this you can tailor the fertilizer application in a given field without additional increase in expenditure on either nutreints or water. Sensor-based fertigation is the latest example in this case.

Right place of application : We need an exercise to know , what is the root distribution pattern ( Both vertically and horizontally to define active root zone) and which nutrient is mobile within soil or plant , accordingly , we have to apply to them within the roots , calle dplacement of fertilizers. This si the reason , why fertigation outsmarts other method sof fertilizer or irrigation . Selection of crop is another issue .

5R.....we often say to apply 4R principles , we need a proper mindset as well...

We have brought these principles to another level of use as Nutrient Expert.....as field application..

Nutrient Expert for Wheathttp://software.ipni.net › topic › wheat

Aqarab Husnain Sir, yes it's completely true. RIGHT TIME is a one principle of 4R concept.

Good question; Yes, what you said is absolutely true.

Timely placement of external material to crops is suitable because, at the right time crops can utilize the external material more efficiently whereas before or after application is nothing but wastage of the applied external material.

It's like we take lunch , dinner and breakfast at definite time , likewise plants also have peak activity time of physiological nutrient demand coinciding with root activity . If we fail in synchronising that , nutrients will no longer be properly utilised and remain unused in soil....

Anoop Kumar Srivastava what you will suggest in order to solve these problems?

Let us put a specific crop to go about solution very specifically....

Also raise a specific input to be applied at what time....

Anoop Kumar Srivastava other problems like temperature either effects the 4R pricipal? If yes then what will be the solution?

Please propose a complete account of very specific problem in one go to get the proper feedback from all participants....

ok thanks

I agree with Dr Anoop.

Absolutely, Anoop Kumar Srivastava has the best knowledge in the field of agricultutre. I really impressive.

Sim muito importante, para evitar perdas. No momento certo (para o estágio da planta e as condições climaticas), na dosagem correta, em alguns casos na sequência certa.

English may be suitable