Discussions regarding coffee nutrition managment with organic inputs
(5/29/02 - 6/3/02)

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postings: 5
countries: Brazil, Nicaragua, United States
organizations/institutions/companies: CATIE, Embrapa Soils, Cornell University, USDA

From: Charles Staver
To: MULCH-L@cornell.edu
Subject: coffee nutrition: total nutrients, timing and biological enhancers
Date: Wed, 29 May 2002

Mulchers,

We at CATIE have been working in the past year with nutrition management of low input, low yielding coffee with organic inputs. This coffee is often found under mature Inga or mixed shade which requires little pruning, but does not provide much litter input. We have been able to work with farmers to do renovation pruning, since the fields are characterized by unproductive wood. However, we would like to find ways to increase the nutrient supply or speed up nutrient cycling so that in a few years the fields have not returned to predominantly unproductive wood. We are trying to put together a more general framework which would allow extensionists and farmers to analyze the situation of their fields, understand the basis for alternative management approaches, and test prototypes of what they consider most viable. I would like to summarize our efforts so far in hopes that someone has ideas, experiences, references or contacts. A few of these issues have been discussed by ! the group over recent years.

We started out with a simple nutrient input-output calculation for this low input low yielding coffee under Inga Shade using numbers for the literature. Over a three to five year period the balance is negative for most elements, especially if coffee wastes are not returned to the field which is often the case. Obviously returning the wastes is a first step, although this material is often used for more cost effective operations like nurseries. The question we posed was how to change the management of the shade tree component to increase nutrient input or the rate of recycling. Data from hedge row pruning suggests that this should be possible, although tree productivity or N fixation may decline in partial shade. The natural leaf fall high in carbon should be complemented by fresh pruned materials with a lower C:N. An additional concern is the focus primarily on nitrogen with leguminous shade trees and options for the low cost management for other elements. Also lots o! f practical issues with farm families with limited labor, limited capital, and low world coffee prices.

We put in some discovery exercises to stimulate extensionist and farmer observation and discussion about the possible nutrient value of different organic amendments. Fresh pruned leaves were incorporated or surface applied to coffee. When we returned to observe in three months we found coffee root proliferation in the mulch materials, even with Inga which is slow to decompose. A microbiologist colleague from CATIE commented that organic amendments should be applied in series so that the proliferated roots can continue to find increased nutrients in the second or third applications. This led us to think about possible efficiencies which we might gain from the timing of applications (as a way to use existing nutrients better or use small gains to more effect). Nutrient uptake by coffee roots has been studied in a few specific climatic zones, but is not known under many situations, especially the effects of prolonged dry seasons. But there seems to be a more theoretical i! ssue here about the importance of timing of organic amendments. Primavesi proposes that a steady supply of balanced nutrients in small quantities may be favorable for efficiency of nutrient use. Roland has also proposed that mulch-based systems base their productivity on steady nutrient availability rather than total availability. What does this mean for efficiency through timing?

From the farmer perspective in Nicaragua, there has been a lot of interest in the preparation and use of "biofermentados". I am not sure what the English equivalent is. They mix fresh cow manure, milk, a sugar source and water and keep it under anaerobic conditions for 3-4 weeks. It is then diluted with water and applied with a backpack sprayer. Informal results propose increased plant vigor and better color, especially after repeated application or in the second year. Those promoting the practice suggest that the biofermentado enhances biological activity. Similarly bokashi is being promoted. Although it is not applied in large amounts, one of its supposed effects is biological enhancement of existing nutrients. In other words, a healthier system. Clearly biological activity has validity in mulch-based agriculture, but how to understand biological enhancers and how to sort through the claims. What is their effect when the system is depleted or when there are nutri! ent imbalances? Do they create a short-term visual improvement without much contribution to yield? What is their long term utility?

So, to end a message which has become a bit wordy, the issues are total nutrient supply, the speed of nutrient cycling which may be related to biological activity, nutrient balance, the timing of nutrient availability, plant response and plant phenology, and the use of biological enhancers. How to analyze the system and decide where to begin. There are lots of research issues here, but for the moment we are interested in a process for working with extensionists and farmers based on observation, experimentation, discovery exercises that aid in understanding the system, in assessing possible options, and in planning the testing of prototypes or small interventions.

Any comments or suggestions? Thanks for your help.

Charles Staver
CATIE program for IPM and coffee agroforestry
Nicaragua

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Date: Thu, 30 May 2002
To: MULCH-L@cornell.edu
From: Yamily Zavala
Subject: Re: coffee nutrition: total nutrients, timing and biological enhancers

Dear Charles,
This is very exciting…. I thought that the coffee nutrient management issue was forgotten specially because of the low world coffee prices. I am a Doctoral Candidate at Cornell University, believe or not working with coffee nutrition. I am evaluating the effect of Al, Ca and Mg on magnesium deficiency and root development.

Venezuela coffee plantations have been characterized to have low productivity, which have been declining over time. What I learned working in these plantations was that the main cause for low production was due to the low area index of the coffee plants. The principal reason was the severity of Mg deficiency in both systems: Shade and Sun coffee. Because of this I wanted to study what was really happening: I was wondering if that situation was due to the low levels of Mg in the soil or it was due to Al toxicity which was causing this problem. What about Ca? Could Ca also be influencing Mg deficiency ?… Any way, That is the reason I am working in this…..

Just to make it short I found that the three elements play an important role in Mg deficiency. Low Mg levels with increasing Al and /or Ca will increase Mg deficiency in the plants. Increasing Mg or Ca levels in plants exposed to increasing Al will reduce the damage of Al toxicity of the root apex… however Mg deficiency were present when increasing Ca levels.. I am working on my data and results now…..

I have some experience with farmer using the “bio-fermented solutions” in Lara State in Vzla. Coffee plants also showed increase on plant vigor and greener color. Even though, they were happy with how the plants look, they have not increased substantially the yield. I found the same problem in this area than in the other regions in Vzla…. I was convinced; it was 100 % Mg deficiency. I recommended to use at least ¼ of the recommended doses of Dolomite for that particulate soil fertility condition. These farms are called Organic Coffee growers, they do not use any chemical and they thought dolomite wasn’t allowed to be used…. They applied it in a small area and they increase the production per plant at least three times. I visit them two years after that recommendation and the plants were still in a very good condition with no Mg deficiency and been the second year with good yield….. I got some picture, before and after…. They decide to apply dolomite combined with the “bio-fermented solutions to all their coffee plots because of the high impact the found. I don’t know what happen after 3 years…. In this case Mg was the limiting element. In other regions could be another element.

I better stop for now.

Yamily Zavala
Cornell University

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From: Donald Kass
To: MULCH-L@cornell.edu
Subject: Re: coffee nutrition: total nutrients, timing and biological enhancers
Date: Thu, 30 May 2002

Dear Yamily,
Coffee is usually considered not to be too sensitive to high Al levels so long as Ca and Mg levels are adequate. However, there are some reports from Guatemala of high mineral N fertilization acidifying soil to the point that Al toxicity was observed. So, high levels of mineral N fertilization can have an unfavorable effect on coffee as well as on the environment. One would assume that some of these problems might be avoided by using organic N sources although they also can acidify the soil since N will still be in the form of the ammonium ion which will release H+ when it is oxidized to nitrate. It is a common practice in Costa Rica to import dolomite to apply to coffee plantations to overcome Mg deficiency--dolomite is a much more economic Mg source than Magnesium sulfate. Of the Central American countries, only Guatemala has commercial sources of dolomite. Whether dolomite or calcium carbonate precipitates in shallow seas depends to some extent on the organisms present and how long shallow sea water sits over the calcium carbonate--sea water contains more Mg than Ca. Because the Mediterranean went through more evaporative cycles than the Caribbean, rocks around the Mediterranean are richer in dolomite. In any case, dolomite can be considered an organic product since it is generally of biological origin. Lower coffee prices have indeed put a damper on coffee research but there might be a place for low input alternatives.

Best regards,

Don

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Date: Fri, 31 May 2002
To: MULCH-L@cornell.edu
From: Yamily Zavala
Subject: Re: coffee nutrition: total nutrients, timing and biological enhancers

Dear Don,
I agree with you. That is true, not only for Coffee, increasing Ca and Mg concentrations have an amelioration effect on Al toxicity in other crops (wheat, maize for example). I was interested in evaluating the Mg deficiency due to the effect of increasing the concentrations of Al, with different levels of Mg or Ca at very low pH.

Do you know what were the symptoms reported to be Al toxicity induced by high N fertilization in Guatemala? Where can I find those reports?

Yamily Zavala
Cornell University

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From: Pedro Freitas
To: MULCH-L@cornell.edu
Subject: ENC: coffee nutrition: total nutrients, timing and biological enhancers
Date: Mon, 3 Jun 2002

Charles Staver and MULCH-L
In order to be less wordy possible, I'd like to remember the importance of soil management on any crop system, specially in coffee plantations.

Experiences with ZERO-TILLAGE SYSTEM for coffee crop plantation are many in Brazil and some of them are related on PLATFORM PLANTIO DIRETO home page [www.embrapa.br/plantiodireto]. Access can be done by accessing "PROBLEMAS E SOLUÇÕES" [http://www.embrapa.br/plantiodireto/ProblemaSolucao/index.htm] choosing the Brazilian word "cafe".

Allow me to remember that, once on Zero-Tillage System, nutrient balance, nutrient availability, plant response and plant phenology, have fundamental alterations which have to be considered, specially because of organic matter and biological activity dynamic changes.

PEDRO FREITAS
Agronomist, Ph.D. in Soil Science - Sustainable Management of Tropical Soils
Agricultural Research - Embrapa Soils