I started the fertilizer regime application on mahogany at four year old plantation in Kerala, India. Of course last year data observation, it show that increase dosage of fertilizer increase the yield with respect to growth parameters such as girth, height and crown width. Evolving appropriate stand management strategies to enhance productivity and thereby reducing the long rotation period has been the basic challenge before the silviculturist. Among the variable silvicultural options, early tree nutrition practices have bagged considerable attention in the recent times in view of their long standing effect on tree growth and productivity. Especially, appropriate inorganic fertilizers in proper dosages promote stand productivity. However, standard fertilizer regimes on most tropical trees are meager. Especially, such information pertaining to mahogany is lacking from Kerala. I will continue this work in coming year also. 

Hi Vikas!

It is very important what you mention and would be interesting to know the results when you have published, just not quite understand if fertilization is doing these during the establishment or midrotation. Regards. Rodolfo

Hi Rodolfo,

Have a look in the pages 54 - 57 of Results and prospects of fertilization in forestry - Bogdanov, S., V. Ilinkin. 2013 (In Bulgarian, but you can translate parts of the books with translate.google.com, (attached).

There you can see that fertilizer increase the:

- yield with respect to growth parameters such as girth and height with 20 - 30 % (in some cases with 80%);

- significantly increases seed performance in the seminal bases and ordinary forests;

- improves the health of the crops.

But this depends on:

- soil characteristics;

- аge of trees;

- the time of fertilization.

Vladimir,

Thanks for the reply! It is also the right thing to say soil conditions, age and timing of fertilizer application, however, the question is addressed under the following conditions:

The fertilizer is applied in plantations with the same soil, with the same age and at the same time, which time is after the last thinning. From there, the fertilizer applied has a cost. The plantation is not fertilized not have that cost, therefore, the incurred cost is recovered at the end of the rotation?

as a general rule, one likes to fertilize later in the life of a stand because the costs are not carried as long.  also, in young stands the weeds often benefit more than the trees but sometimes it is necessary to get the trees off to a good start.

as to whether it pays, one needs to compare fertilized and not.  a soil analysis to determine the status of the nutrient to be added, usually N, would help one decide how limiting the nutrient is and thus how large a response one might get.

but fertilizing after thinning could be a good time for doing it.

Carl, perhaps lacked add in the question that is sought is that most of the fertilizer is used by plants, for which the application of the same should be done in combination with herbicide or weed control so that they do not use fertilizer intended for the target plants. Also, the comparison is made with fertilized and unfertilized treatments established under the same environmental conditions.

However, under these concepts, you think that initial cost incurred by fertilization is then offset by increased wood? You know some paper to analyze these costs?

obviously weed control can be done but not necessarily and is an extra cost and all those costs come near the beginning of a rotation which means they have to be carried the most years.

  i am far from an economist but believe it should not be too difficult to keep track of the costs and do a simple present net worth comparison of fertilized and not fertilized.  this is often complicated by the rotation length of the fertilized stand being shorter than the non fertilized.  most any resource economist should be able to help you with this.

fertilization can be profitable but it depends on a number of factors.  the lack of the nutrient to be applied is one of the most important. 

Yes, it is very profitable. The return on capital employed on the fertilizing investment in Southern Finland is usually 20-25 percent. The added wood yield is substantial, and liquidation follows soon. But the bad environmental reputation of fertilization makes it unpopular here - and surely there is some justification to it.

Hello Rudolfo.

We did not find a significant efect in timber production of one single distribution of fertilizer at mid-rotation of E. globulus plantations in Central Western Portugal. You may find the results on:

Carneiro, M., António Fabião, M. C. Martins, André Fabião, M. Abrantes da Silva, L. Hilário, M. Lousã & M. Madeira (2008). Effects of harrowing and fertilisation on understory vegetation and timber production of a Eucalyptus globulus Labill. plantation in Central Portugal. Forest Ecology and Management 255, 591-597. [DOI 10.1016/j.foreco.2007.09.028].

There is a copy here in  Research Gate.

Under the financial point of view the increase in timber production was not clearly compensatory, but it may have been an indirect benefict from the decrease on wildfire risk when the fertilization was performed together with harrowing to incorporate into the soil the fertilizer and the understory vegetation residues.

It is a good question for everyone. the problem of administration of nutritional supplements for soil produce a quantity of biomass is greather or less than it would have been under normal circumstances, I consider that in this case this should be coordinated with local market of biomass, or the handling onners as an example, the total costs of production and the energy obtained.

Sauli,

It is very interesting data that is mentioning, since 20-25% increase in the time of planting can result in significant financial returns.

About what you mention the negative environmental reputation fertilization had ever heard. In our region we have big problems related to monoculture pine plantations, then all the problems surrounding plantations are attributed to them!

António,

thanks for the tip of the publication, which'm reading shortly! It is also very important to know that while further growth for fertilizer aplicaión not offset the cost disbursed, was indirect effects. I mention this because in our region canopy openness with fertilizer application improves conditions for understory vegetation and ends in an adverse effect on the management of the plantation.

Hola Fito yo te escribo en español. Lo que se puede hacer es tener el dato del costo de fertilización en el año n y capitalizar ese valor al momento de la corta. Luego se compara con valores de madera o rendimiento en $/ha sin fertilizar y con fertilización, si ese incremento de volumen por ha (expresado en $/ha) es mayor al valor del costo de fertilización capitalizado n años estamos bien, si no es mayor no se justifica la fertilización.. Un abrazo.

Ok, eso en cuanto a los costos y beneficios directos, pero conoces algún trabajo relacionado que estudie este tema, donde incluya por ejemplo la reposición de fertilizante como efecto positivo al ambiente? Estaría bueno, mas allá del incremento directo por efecto de la fertilización, analizar los efectos positivos que ello podría tener como por ejemplo, mantener la capacidad productiva del sitio. Habría que armar un equipo interdisciplinario y avanzar, creo que podría ser de gran interés para el sector. Y no solo en fertilización en medio término, sino también en fertilización inicial. Saludos!

Fito gracias por tu respuesta. En principio no conozco bibliografía en este tema si bien lo mio es relacionado al ambiente, pero no específicamente en ese tema, ya que me desenvuelvo en servicios ambientales con énfasis en bosques nativos. Sin embargo, estoy abierto a aprender de servicios ambientales en plantaciones y a aportar y sumarme en lo que consideres oportuno. Un abrazo  

Miguel, ni bien tenga un tiempito voy a ordenar datos de ensayos de aplicación de fertilizantes y trataré de simular el crecimiento hasta el final del turno. Trataremos de aplicar los costos a cada actividad y obtendremos la relación directa. Solo que tendremos que pensar bastante para poner valores a los costos indirectos, o mejor dicho, a los beneficios futuros que podría ocasionar esa fertilización! Un abrazo!  

There is no general answer as to economics of fertilization in forests.   First point is to be certain that the suspect nutrient deficit is well understood.  Some can be subtle and go unnoticed.   Timing may be critical, depending on whether you are trying to give a seedling a burst of growth to outgrow competing vegetation, or to boost growth on well-established trees toward end of rotations.  As one of your commentators already noted, you can end up fertilizing your weeds.   In temperate areas, fertilizing at planting time incurs horrendous interest costs over the rotation. 

Examples:  private owners are fertilizing douglas fir in Oregon, even on pretty good soils.   Also on industry land in the South,  where sites are often dry and soils degraded by past farm practices.  You could probably learn from their experiences.    I have no convenient references but they would be easy to find.

If you are in an area where aerial application of fertilizers/herbicides is extensively practiced, the aircraft will be at hand.  If not,  harder.

In Indonesia, the paper cos. use a dab of fertilizer in the soil mix delivered with seedlings -- precise application.  No runoff into the streams.  But there the rotation is 7 years -- and payback is very good.

Again, no general answer.    Developing the approach usually takes a lot of consulting with experts and still, trial and error,

Best of luck   LCI

Ok Fito cuando quieras aplicamos lo que necesites. Un abrazo

Loyd, their response is very good. There is clearly much to advance the issue. I think we should move forward in discovering the indirect benefits of fertilization. The question is mainly aimed to identify whether someone has already worked on combining production-economy-environment on this issue. For determining the benefit of fertilization, such as replenishing nutrients exported during harvest and put a price on this is not easy. Thanks again for your reply and as soon as we progress regarding improvement course. regards

Hi again,

Surely someone is looking at  economy-production-environmental issues.   I have not bumped into it myself, perhaps cuz in the Northeast US where I work fertilizing is uncommon.

Find Tappeiner, et al, Silviculture and ecology in western US forests.  Oregon State Univ Press, 2007.  There is a section on fertilization.  Will give yo a place to start.

Get in touch w. them for more advice, and contact Dan Richter at Duke University-- I bet he will be well informed on these issues.

Years ago a scientist named George Bengston did a short paper where he estimated the nutrient losses in removing tops,  in southern pine, and then figured out what it would cost to replace them by fertilizing. Ingenious, and convincing.  It was not trivial.  As a first step you need not go farther than this.  Plainly results will be site-specific.  This probably connects to low-impact harvesting as leaving more biomass behind moderates nutrient losses.  

IN some temperate soils, with long enough rotations, nutrient losses are replaced by weathering.  Not likely in many tropical soils. 

Here is where the area being studied matters.  The need for fertilizer for production,  and dynamics of its flow to the environment, will differ between temperate,  high altitude, and lowland tropical situations.  

Would seem that just assessing the production/financial benefit of fertilizing is one place to begin -- if it's not worth doing,  then need not pursue environmental issues further.

Nest  LCI

Lloyd, very true what you say! I will seek references and I will start working on the issue. It really is a challenge to put value on anything that does not have an immediate economic return.

 I think this is conditioned by many factors. My experience in southern Spain with Eucalyptus globulus is that it is financially justifed, the investment. But we are  talking about a species of rapid growth in soils of very low fertility and under conditions influenced  by the Mediterranean climate,

Hi, Rodolfo.

Financial profitability of fertilization in forest plantation has to do mainly with the limitation degree of the nutrients you apply.  If you apply the nutrients that are limiting growth in your site, then it is highly probable that the operation will be profitable.  If you apply non-limiting nutrients, then you can even decrease tree growth. Moreover, if any other factor such as inter or intraspecific competition is taking place in your plantation, financial profitability of fertilizer application will be little likely.  In such case, you should correct that situation first (i.e. thinning).  

Cheers!!

miguel is correct about needing to apply a nutrient that is lacking.  nitrogen is the most commonly used fertilizer.  but if the site quality is poor, although you can get a large percentage increase in growth, the actual amount of increase, which is related the profit from fertilizing, can be small.  fertilization should be done on potentially good quality sites that are lacking a nutrient to be good quality

carl

Miguel, is right what you say. In our region we have low availability of P, so the fertilization with P are generally positive. N is not lacking, so the fertilization with N, as you point out, the plants grow less than those unfertilized. Now, if you take into account all these factors, applying fertilizer (P in our case) after thinning, increased growth of the plantation (wood extra fertilizer application) could exceed the cost incurred during the fertilization?

On the other hand, if we consider not only the direct results in the short term, for example to return nutrients regardless of increased wood, you think we could evaluate those services that are not valued in the short term? We should consider?

regards

wen deciding if fertilization is a good investment, te financial reward should be given first consideration but other impacts should certainly be considered.  also remember that the increase in growth is likely just a short term response as the fertilizer is taken up by the plants and those reduced in amount in the soil so the response lessons with time, often a few years.

Hi, Rodolfo.  If you have determined that P is the limiting nutrient in your plantation, financial profitability of application of P is very likely, especially if you apply the correct dose of P. As Carl points out, nutrients applied will expire within a few years (probably four to six years after application).  By that time, you shoud make another nutrient diagnosis and apply what needed.