Category Archives: Agriculture

How to Improve the Quality of Your Soil

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Soil is important, whether you’re growing prize winning roses, landscape shrubs or your own fruit trees. All need to be in the right type of soil to get the nutrient they need. Even beginners can improve the quality of the soil in the garden. All you need to do is follow these simple steps:

1. Add Compost

Compost is not just for preparing the beds in the spring. Compost can be placed into your raised beds in the fall and improve their conditions over the winter. Because they will be sitting over the beds all winter, this doesn’t even have to be completely broken down compost either. A lot of the process will happen right there on the bed.

compost-organic-waste-farming

The concept of safe food using organic waste generated compost is picking up in South Asia

You can even use this method as a practical way of getting rid of all the waste you pick up from your garden in the fall. Just spread this over the bed and cover with mulch. The mulch protects the soil and the nutrients in the compost.

2. Use Soil Amendments

Different soil amendments can be added to your soil to make it more suitable to your purposes. Choosing which soil amendment to use with your sol will be a matter of matching the proper solution to the problem you are facing. For example, there are amendment for increasing the nutritional content of your soil and others for improving the soil’s texture also known as tilth. For example, if your notice that the water is draining away too fast, you can add an amendment that allows you to soak up the moisture and the reverse is also true.

You can adjust the conditions of the soil to your exact needs with the right soil amendment. This could be compost or other rich matter that absorbs moisture or an amendment like greensand that allows water to drain away more easily.

Here are some common soil amendments that you can consider using for your garden as needed:

  • vermiculite (worm castings)
  • compost
  • greensand (or green sand)
  • grass clippings
  • cornmeal
  • alfalfa meal
  • straw
  • kelp meal

3. Plant a Cover Crop

When you are thinking about improving soil quality, don’t forget the power of cover crops. This is not just an idea for large scale agricultural weed suppression. They are also a major benefit for backyard gardeners as well.

Cover crops are especially good for treating the soil as they provide oxygenation and improved nutrient availability. Alfalfa with its very deep root system pulls nutrients upwards from the lower levels of soil and make these more available in planting season. Then a couple weeks before you begin planting, this cover crop will be tilled back into the soil, increasing its organic composition and nutrient content.

This can also be used to improve the levels of nitrogen in the soil when using legumes as a cover crop. Fava beans, crimson clover and alfalfa are all good examples of nitrogen high crop covers. If you will not be growing anything particular over the growing season, you may consider a cover crop that protect and aerate your beds. (Pro tip: cherry trees are a great choice for the beginner backyard orchardist and benefit greatly from good soil).

4. Try Lasagna Gardening

Also called sheet composting or “No-Till” gardening is another good way to improve your gardens soil quality and a perfect way to begin your raised beds and continue them. As you notice the quality levels of soil in your bed begin dropping down, you will keep adding new layers like lasagna which begins improving the quality of your soil from the top to the bottom. After the end of each growing season new layers are added.

For more information about your garden and the process of sheet composting, check out this article on the lasagna gardening method beginner’s guide. But there is one thing you will need to consider when using the lasagna method of composting. If you will be renovating your raised beds with the sheet composting method, you will need to wait a full 6-months before planting as you will need them to fully break down.

So this method will be best suited to those garden working with rotating beds or those gardeners who only plant one season. The following link included here will give some pointers on how this can be changed about and planting can be done sooner. Basically, if you would like to begin planting sooner, you will need to spread out a layer of compost and or healthy topsoil –– roughly 2 or 3 inches thick. You can then begin planting directly through this top layer.

5. Prepare Raised Beds for the Winter

Never forget the importance of using the end of the year garden season is your opportunity to improve the quality of your soil in a number of ways. This end of the year ritual is like “closing down the shop” till spring. But, if you live in a warmer area of the country this might not even be necessary.

Here are some things to do. First, cut the plants as opposed to pulling them from the soil. Cutting the plant will allow the roots to rot away and this will make your soil lighter and airy. Then you can spread some compost out on the soil and cover this with a layer of mulch, the compost will be feeding nutrients back to the soil while the mulch will protect the soil and keep the nutrients bound in.

You can also just plant a cover crop and call it a year. Be sure to check out our article on winter gardening for some more things to do in the cold months.

Charcoal Briquette Production in the Middle East: Perspectives

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There is a huge demand for charcoal briquettes in the Middle East, especially in Saudi Arabia, Egypt and UAE. However the production of charcoal in the Middle East is in nascent stages despite the availability of biomass resources, especially date palm biomass. The key reason for increasing demand of charcoal briquettes is the large consumption of meat in the region which uses charcoal briquettes as fuel for barbecue, outdoor grills and related activities.

The raw materials for charcoal briquette production are widely available across the Middle East in the form of date palm biomass, crop wastes and woody biomass. With a population of date palm trees of 84 million or 70% of the world’s population, the potential biomass waste from date palm trees is estimated at 730,000 tons / year (approximately 200,000 tons from Saudi Arabia and 300,000 tons from Egypt). Date palm trees produce huge amount of agricultural wastes in the form of dry leaves, stems, pits, seeds etc. A typical date tree can generate as much as 20 kilograms of dry leaves per annum while date pits account for almost 10 percent of date fruits.

The fronds and trunks of date palm trees are potential raw materials for charcoal because of the potential to produce high calorific value and low ash content charcoal. Leaf waste will produce a low calorific value due to high ash content. In addition, woody biomass waste such as cotton stalks that are widely available in Egypt can also be a raw material for making charcoal. The contribution of the agricultural sector in Egypt is quite high at 13.4%.

Charcoal is compacted into briquettes for ease in handling, packaging, transportation and use. Briquettes can be made in different shapes such as oval, hexagonal, cube, cylinder or octagonal. An adhesive (called binder) is needed for the manufacture of the briquette. Two common binders are saw dust and corn starch.

Date palm biomass is an excellent resource for charcoal production in Middle East

Continuous pyrolysis is the best technology for charcoal production. Continuous pyrolysis has the ability to handle large biomass volumes, the process is fast and smoke production is negligible. When using conventional pyrolysis technology  (or batch carbonization), the process is lengthy, processing capacity is small and there are concerns related to harmful smoke emissions.

Apart from charcoal, continuous pyrolysis also gives bio oil, wood vinegar and syngas. Syngas can be converted into electricity by using a gas engine or converted into a wide variety of biofuels through different processes. Bio oil can be used as boiler fuel and marine fuel. Wood vinegar can be used as biopesticide and liquid organic fertilizer. Low water content in date palm waste fronds and trunks make it very suitable for thermochemical conversion technologies, especially pyrolysis and gasification.

 

Charcoal can also be used for the production of activated charcoal/carbon. Activated carbon is used by a lot of industries for purification processes. In addition, a number of industries that are using petcoke as fuel can switch to charcoal due to its better combustion properties and eco-friendly nature.

For more information on how to set up charcoal production plant based on date palm biomass or other crop residues in the Middle East, please email salman@bioenergyconsult.com or eko.sb.setyawan@gmail.com

7 Crop Health Metrics That Matter to Farmers

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Crop health is of paramount importance to farmers; thus, careful and consistent monitoring of crop health is an absolute must. A recent study on coffee yield losses from 2013 to 2015 revealed that pests and diseases led to high primary (26%) and secondary (38%) yield losses in the researcher’s sampled area. This highlights the significance of closely paying attention to such detrimental factors in your crop’s environment. Doing so will ensure maximum yield and profit for farmers come harvest time.

land clearing machinery for biofuels sector

To look at crop health monitoring as governed by just one or two aspects, however, is a serious mistake. Rather, a holistic approach must be adopted; in other words, more factors need to be monitored than just pestilence and disease.

Here are seven of the most important crop health metrics for farmers to monitor, based on the Sustainable Agriculture Research & Education (SARE) Program’s guidelines.

1. Crop appearance

Perhaps the most obvious indicator of crop health is their general appearance. While not an all-in-one, foolproof method of gauging the current condition of a particular set of crops, a farmer possessing the right tools and knowledge can tell quite a lot from simply looking at the state of his or her plants.

Lightness or discoloration in foliage more often than not points to chlorosis, a state in which plants produce insufficient chlorophyll. Modern methods of crop health monitoring, including new technologies that utilize both near-infrared and visible light, allow farmers to actively and accurately monitor chlorophyll content.

2. Crop growth

Among the indicators of poor crop growth are short branches, sparse stand, and the rarity or absence of new shoots. This, of course, will inevitably affect your total yield in a negative way. Under ideal circumstances, there should be robust growth and dense, uniform stand in your crops.

3. Tolerance or resistance to stress

Simply put, crop stress is a decrease in crop production brought about by external factors. An example would be exposure to excess light and high temperatures, which may disrupt photosynthesis (known as photoinhibition). As a result, crops will have insufficient energy to bear fruit or grow, and may even sustain lasting damage to their membranes, chloroplasts, and cells. Healthy crops are stress-tolerant, and can easily bounce back after being exposed to stressors in their environment.

4. Occurrences of pests and diseases

An indicator that your crops are extremely susceptible to pests and diseases would be if over 50% of the population ends up getting damaged by said factors. Under the right circumstances, less than 20% of your crops would be negatively affected by any invasion of pests or spread of disease, allowing them to easily recuperate and increase in number once more.

Building crop resistance against harmful insects and diseases can be done in a number of ways, including improving crop diversity, crop rotation, using organic pesticides such as Himalayan salt spray and eucalyptus oil, and even genetic research and enhancement.

5. Weed competition and pressure

Apart from insects and plant diseases, weeds can also spell doom for your crops, if left unchecked. In the event that your farm becomes overpopulated with weeds that will steal the nutrients from your crops, you will certainly notice that your crops are steadily dwindling. Healthy crops, on the other hand, would eventually overwhelm the weed population and reclaim dominance over your field.

6. Genetic diversity

To have only one dominant variety of crop in your farm is tantamount to putting your eggs in a single basket. For instance, you should consider the importance of having multiple disease-resistant crop varieties on your farm. Don’t fall prey to the temptation of replacing them entirely with a single, higher-yielding type.

It is essential to build crop resistance against harmful insects and diseases

7. Plant diversity and population

In an ideal setting, there should be more than two species of plants in your field. Counting the actual number of trees or plants across your farm, as well as the naturally occurring vegetation on all sides of the area, can also give you a better perspective on your farm’s overall crop health.

Importance of crop management system

Some farmers become overly reliant on insecticides and other chemicals to eliminate their pest problems — a grievous error, as this will likely lead to even more serious problems. Even the indiscriminate application of mineral fertilizers may inadvertently boost pest populations by making conditions ideal for them to thrive.

Ultimately, a combination of the right knowledge and the proper technology is a must in measuring and monitoring crop health metrics. Farmers must always be aware of the current health of their crops, and must be prepared to address any problems with solutions that don’t end up causing more.

Agricultural Wastes in the Philippines

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The Philippines is mainly an agricultural country with a land area of 30 million hectares, 47 percent of which is agricultural. The total area devoted to agricultural crops is 13 million hectares distributed among food grains, food crops and non-food crops. Among the crops grown, rice, coconut and sugarcane are major contributors to biomass energy resources.

The most common agricultural wastes in the Philippines are rice husk, rice straw, coconut husk, coconut shell and bagasse. The country has good potential for biomass power plants as one-third of the country’s agricultural land produces rice, and consequently large volumes of rice straw and hulls are generated.

Rice is the staple food in the Philippines. The Filipinos are among the world’s biggest rice consumers. The average Filipino consumes about 100 kilograms per year of rice.  Though rice is produced throughout the country, the Central Luzon and Cagayan Valley are the major rice growing regions. With more than 1.2 million hectares of rain-fed rice-producing areas, the country produced around 19 million tons of rice in 2019.

The estimated production of rice hull in the Philippines is more than 2 million tons per annum which is equivalent to approximately 5 million BOE (barrels of oil equivalent) in terms of energy. Rice straw is another important biomass resource with potential availability exceeding 5 million tons per year across the country.

rice-biomass-philippines

With the passing of Biofuels Act of 2006, the sugar industry in the Philippines which is the major source of ethanol and domestic sugar will become a major thriving industry. Around 380,000 hectares of land is devoted to sugarcane cultivation. It is estimated that 1.17 million tonnes of sugarcane trash is recoverable as a biomass resource in the Philippines.

In addition, 6.4 million tonnes of surplus bagasse is available from sugar mills. There are 29 operating sugar mills in the country with an average capacity of 6,900 tonnes of cane per day. Majority is located in Negros Island which provides about 46% of the country’s annual sugar production.

The Philippines has the largest number of coconut trees in the world as it produces most of the world market for coconut oil and copra meal. The major coconut wastes include coconut shell, coconut husks and coconut coir dust. Coconut shell is the most widely utilized but the reported utilization rate is very low.  Approximately 500 million coconut trees in the Philippines produce tremendous amounts of biomass as husk (4.1 million tonnes), shell (1.8 million tonnes), and frond (4.5 million tonnes annually).

Maize is a major crop in the Philippines that generates large amounts of agricultural residues. It is estimated that 4 million tonnes of grain maize and 0.96 million tonnes of maize cobs produced yearly in the Philippines. Maize cob burning is the main energy application of the crop, and is widely practiced by small farmers to supplement fuelwood for cooking.

If you want to know about sustainable rice farming practices, check this link.

Biomass Sector in India – Problems and Challenges

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Biomass power plants in India are based mostly on agricultural wastes. Gasifier-based power plants are providing a great solution for off-grid decentralized power and are lighting homes in several Indian states. While for providing grid-based power 8-15 MW thermal biomass power plants are suitable for Indian conditions, they stand nowhere when compared to power plants being set up in Europe which are at least 20 times larger.

biomass_India

Energy from biomass is reliable as it is free of fluctuation unlike wind power and does not need storage to be used in times of non-availability as is the case with solar. Still it is not the preferred renewable energy source till now, the primary reason that may be cited is the biomass supply chain.

Biomass availability is not certain for whole year. Biomass from agriculture is available only after harvesting period which can stretch only for 2-3 months in a year. So there is a need to procure and then store required quantity of biomass within this stipulated time.

Some of the Indian states leading the pack in establishing biomass-based power projects are Karnataka, Andhra Pradesh, and Maharashtra. Ironically, states having agricultural-based economy have not properly been able to utilize the opportunity and figure low on biomass energy utilization. Only Uttar Pradesh has utilized large part of the biomass potential in north Indian States and that is mainly due to the sugarcane industry and the co-generation power plants.

Interestingly Punjab and Haryana don’t have much installed capacity in comparison to potential even though tariff rates are more than Rs. 5 per unit, which are better than most of the states. This can be attributed to the fact that these tariffs were implemented very recently and it will take time to reflect the capacity utilization.

Table: Biomass Potential and Installed Capacity in Key Indian States

State

 Power Potential (MWe) Installed Capacity (by 2011)

Tariff
Punjab 2413.2 74.5

@ Rs 5.25 per unit, (2010-11)
Uttar Pradesh 1594.3 592.5 @ Rs 4.70
Haryana 1120.8 35.8 @Rs 5.24 per unit
Rajasthan 1093.5 73.3

@ Rs 4.72/unit water cooled (2010-11)
Maharashtra 1014.2 403 @ Rs 4.98 (2010-11)
Madhya Pradesh 841.7 1.0

@ Rs 3.33 to 5.14/unit paise for 20 years with escalation of 3-8 paise
Karnataka 631.9 365.18

@ Rs 3.66 per unit (PPA signing date)

Rs 4.13 (10th year)
Andhra Pradesh 625 363.25 @ Rs 4.28 per unit  (2010-11)
Gujarat 457.7 0.5

@ Rs 4.40 per unit (with accelerated depreciation)
Chhattisgarh 248.5 231.9 @Rs 3.93 per unit (2010-11)
Kerala 195.9 – @ Rs 2.80 per unit escalated at 5% for
five years (2000-01
Source: Biomass Atlas by IISc, Bangalore and MNRE website

The electricity generation could be cheaper than coal if biomass could be sourced economically but ssome established biomass power plants tend to misuse the limit of coal use provided to them (generally 10-15% of biomass use) to keep it operational in lean period of biomass supply. They are not able to run power plants solely on biomass economically which can be attributed to :

  • Biomass price increases very fast after commissioning of power project and therefore government tariff policy needs an annual revision
  • Lack of mechanization in Indian Agriculture Sector
  • Defragmented land holdings
  • Most of the farmers are small or marginal

Government policy is the biggest factor behind lack of investment in biopower sector in states with high biomass potential. Defragmented nature of agricultural lands do not allow high mechanization which results in reduction of efficiency and increase in procurement cost.

Transportation cost constitutes a significant portion of  the costs associated with the establishment and running of biomass power plants. There is need of processing in form of shredding the biomass onsite before transportation to increase its density when procurement is done from more than a particular distance. While transportation in any kind or form from more than 50 Km becomes unviable for a power plant of size 10-15MW. European power plants are importing their biomass in form of pellets from other countries to meet the requirement of the huge biopower plants.

Not all the biomass which is regarded as agri-waste is usually a waste; part of it is used as fuel for cooking while some part is necessary to go back to soil to retain the soil nutrients. According to conservative estimates, only two-third of agricultural residues could be procured for power production.

And as human mentality goes waste is nothing but a heap of ash for the farmer till someone finds a way to make profit out of it, and from there on the demand of waste increases and so its price. Though there is nothing wrong in transferring benefits to the farmers and providing them a competitive cost of the agri-waste but operations becomes increasingly unviable with time.

A robust business model is necessary to motivate local entrepreneurs to take up the responsibility of supplying biomass to processing facilities. Collection centres covering 2-3 villages can be set up to facilitate decentralization of biomass supply mechanism. Biomass power plant operators may explore the possibility of using energy crops as a substitute for crop wastes, in case of crop failure. Bamboo and napier grass can be grown on marginal and degraded lands.

Rice Straw As Bioenergy Resource

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The cultivation of rice results in two types of biomass residues – straw and husk – having attractive potential in terms of energy. Rice husk, the main by-product from rice milling, accounts for roughly 22% of paddy weight, while rice straw to paddy ratio ranges from 1.0 to 4.3. Although the technology for rice husk utilization is well-established worldwide, rice straw is sparingly used as a source of renewable energy. One of the main reasons for the preferred use of husk is its easy procurement. In case of rice straw, however, its collection is difficult and its availability is limited to harvest time.

Rice_straw

Rice straw can either be used alone or mixed with other biomass materials in direct combustion, whereby combustion boilers are used in combination with steam turbines to produce electricity and heat. The energy content of rice straw is around 14 MJ per kg at 10 percent moisture content.  The by-products are fly ash and bottom ash, which have an economic value and could be used in cement and/or brick manufacturing, construction of roads and embankments, etc.

Straw fuels have proved to be extremely difficult to burn in most combustion furnaces, especially those designed for power generation. The primary issue concerning the use of rice straw and other herbaceous biomass for power generation is fouling, slagging, and corrosion of the boiler due to alkaline and chlorine components in the ash. Europe, and in particular, Denmark, currently has the greatest experience with straw-fired power and CHP plants.

Because of the large amount of cereal grains (wheat and oats) grown in Denmark, the surplus straw plays a large role in the country’s renewable energy strategy. Technology developed includes combustion furnaces, boilers, and superheat concepts purportedly capable of operating with high alkali fuels and having handling systems which minimize fuel preparation.

A variety of methods are employed by the European plants to prepare straw for combustion. Most use automated truck unloading bridge cranes that clamp up to 12 bales at a time and stack them 4-5 bales high in covered storage. Some systems feed whole bales into the boiler. Probably the best known whole bale feeder is the “Vølund cigar feeding” concept, originally applied by Vølund (now Babcock and Wilcox-Vølund). Whole bales are pushed into the combustion chamber and the straw burned off the face of the bale.

However, the newer Danish plants have moved away from whole-bale systems to shredded straw feed for higher efficiency. For pulverized coal co-firing, the straw usually needs to be ground or cut to small sizes in order to burn completely within relatively short residence times (suspension fired systems) or to feed and mix upon injection with bed media in fluidized bed systems.

The chemical composition of feedstock has a major influence on the efficiency of biomass cogeneration. The low feedstock quality of rice straw is primarily determined by high ash content (10–17%) as compared with wheat straw (around 3%) and also high silica content in ash. On the other hand, rice straw as feedstock has the advantage of having a relatively low total alkali content, whereas wheat straw can typically have more than 25% alkali content in ash.

However, straw quality varies substantially within seasons as well as within regions. If straw is exposed to precipitation in the field, alkali and alkaline compounds are leached, improving the feedstock quality. In turn, moisture content should be less than 10% for combustion technology.

In straw combustion at high temperatures, potassium is transformed and combines with other alkali earth materials such as calcium. This in turn reacts with silicates, leading to the formation of tightly sintered structures on the grates and at the furnace wall. Alkali earths are also important in the formation of slag and deposits. This means that fuels with lower alkali content are less problematic when fired in a boiler.

Rationale for Biomass Supply Chain

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Biomass resources have been in use for a variety of purposes since ages. The multiple uses of biomass includes usage as a livestock or for meeting domestic and industrial thermal requirements or for the generation of power to fulfill any electrical or mechanical needs. One of the major issues, however, associated with the use of any biomass resources is its supply chain management.

The resource being bulky, voluminous and only seasonally available creates serious hurdles in the reliable supply of the feedstock, regardless of its application. The idea is thus to have something which plugs in this gap between the biomass resource availability and its demand.

The Problem

The supply chain management in any biomass-based project is nothing less than a big management conundrum. The complexity deepens owing to the large number of stages which encompass the entire biomass value chain. It starts right from the resource harvesting and goes on to include the resource collection, processing, storage and eventually its transportation to the point of ultimate utilization.

Owing to the voluminous nature of the resource, its handling becomes a major issue since it requires bigger modes of logistics, employment of a larger number of work-force and a better storage infrastructure, as compared to any other fuel or feedstock. Not only this their lower energy density characteristic, makes it inevitable for the resource to be first processed and then utilized for power generation to make for better economics.

All these hassles associated with such resources, magnify the issue of their utilization when it comes to their supply chain. The seasonal availability of most of the biomass resources, alternative application options, weather considerations, geographical conditions and numerous other parameters make it difficult for the resource to be made consistently available throughout the year. This results in poor feedstock inputs at the utilization point which ends up generating energy in a highly erratic and unreliable manner.

The Solution

Although most of the problems discussed above, are issues inherently associated with the usage of biomass resources, they can be curtailed to a larger extent by strengthening the most important loophole in such projects – The Biomass Resource Supply Chain.

World over, major emphasis has been laid in researching upon the means to improve the efficiencies of such technologies. However, no significant due diligence has been carried out in fortifying the entire resource chain to assure such plants for a continuous resource supply.

The usual solution to encounter such a problem is to have long term contracts with the resource providers to not only have an assured supply but also guard the project against unrealistic escalations in the fuel costs. Although, this solution has been found to be viable, it becomes difficult to sustain such contracts for longer duration since these resources are also susceptible to numerous externalities which could be in the form of any natural disaster, infection from pests or any other socio-political or geographical disturbances, which eventually lead to an increased burden on the producers.

Agricultural Wastes in the Middle East

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Agriculture plays an important role in the economies of most of the countries in the Middle East. The contribution of the agricultural sector to the overall economy varies significantly among countries in the region, ranging, for example, from about 3.2 percent in Saudi Arabia to 13.4 percent in Egypt. Large scale agricultural irrigation is expanding, enabling intensive production of high value cash and export crops, including fruits, vegetables, cereals, and sugar.

The term ‘crop residues’ covers the whole range of biomass produced as by-products from growing and processing crops. Crop residues encompasses all agricultural wastes such as bagasse, straw, stem, stalk, leaves, husk, shell, peel, pulp, stubble, etc. Wheat and barley are the major staple crops grown in the Middle East region. In addition, significant quantities of rice, maize, lentils, chickpeas, vegetables and fruits are produced throughout the region, mainly in Egypt, Syria, Saudi Arabia and Jordan.

Agricultural Wastes in the Middle East

Large quantities of agricultural wastes are produced annually in the Middle East, and are vastly underutilised. Current farming practice in the Middle East is usually to plough these residues back into the soil, or they are burnt, left to decompose, or grazed by cattle. These residues could be processed into liquid fuels, solid fuels or thermochemically processed to produce electricity and domestic heat in rural areas.

date-palm-waste

Date palm biomass is an excellent resource for charcoal production in Middle East

Date palm is one of the principal agricultural products in the arid and semi-arid region of the world, especially Middle East and North Africa (MENA) region. The Arab world has more than 84 million date palm trees with the majority in Egypt, Iraq, Saudi Arabia, Iran, Algeria, Morocco, Tunisia and United Arab Emirates.

Date palm trees produce huge amount of agricultural wastes in the form of dry leaves, stems, pits, seeds etc. A typical date tree can generate as much as 20 kilograms of dry leaves per annum while date pits account for almost 10 percent of date fruits. Some studies have reported that Saudi Arabia alone generates more than 200,000 tons of date palm biomass each year.

In Egypt, crop residues are considered to be the most important and traditional source of domestic fuel in rural areas. These crop residues are by-products of common crops such as cotton, wheat, maize and rice. The total amount of residues reaches about 16 million tons of dry matter per year.

Cotton residues represent about 9% of the total amount of residues. These are materials comprising mainly cotton stalks, which present a disposal problem. The area of cotton crop cultivation accounts for about 5% of the cultivated area in Egypt.

A cotton field in Egypt

Energy crops, such as Jatropha, can be successfully grown in arid regions for biodiesel production. Infact, Jatropha is already grown at limited scale in some Middle East countries and tremendous potential exists for its commercial exploitation.

Date Palm Wastes as a Biomass Resource

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Date palm is one of the principal agricultural products in the arid and semi-arid region of the world, especially Middle East and North Africa (MENA) region. There are more than 120 million date palm trees worldwide yielding several million tons of dates per year, apart from secondary products including palm midribs, leaves, stems, fronds and coir. The Arab world has more than 84 million date palm trees with the majority in Egypt, Iraq, Saudi Arabia, Iran, Algeria, Morocco, Tunisia and United Arab Emirates.

date-wastes

Date palm biomass is found in large quantities across the Middle East

Egypt is the world’s largest date producer with annual production of 1.47 million tons of dates in 2012 which accounted for almost one-fifth of global production. Saudi Arabia has more than 23 millions date palm trees, which produce about 1 million tons of dates per year.

Biomass Potential of Date Palm Wastes

Date palm trees produce huge amount of agricultural wastes in the form of dry leaves, stems, pits, seeds etc. A typical date tree can generate as much as 20 kilograms of dry leaves per annum while date pits account for almost 10 percent of date fruits. Some studies have reported that Saudi Arabia alone generates more than 200,000 tons of date palm biomass each year.

Date palm is considered a renewable natural resource because it can be replaced in a relatively short period of time. It takes 4 to 8 years for date palms to bear fruit after planting, and 7 to 10 years to produce viable yields for commercial harvest. Usually date palm wastes are burned in farms or disposed in landfills which cause environmental pollution in dates-producing nations. In countries like Iraq and Egypt, a small portion of palm biomass in used in making animal feed.

The major constituents of date palm biomass are cellulose, hemicelluloses and lignin. In addition, date palm has high volatile solids content and low moisture content. These factors make date biomass an excellent waste-to-energy resource in the MENA region.

Technology Options for Date Palm Biomass Utilization

A wide range of thermal and biochemical technologies exists to tap the energy stored in date palm biomass to useful forms of energy. The low moisture content in date palm wastes makes it well-suited to thermochemical conversion technologies like combustion, gasification and pyrolysis which may yield steam, syngas, bio oil etc.

On the other hand, the high volatile solids content in date palm biomass indicates its potential towards biogas production in anaerobic digestion plants, possibly by codigestion with sewage sludge, animal wastes and/and food wastes. The cellulosic content in date palm wastes can be transformed into biofuel (bioethanol) by making use of the fermentation process.

The highly organic nature of date palm waste makes it highly suitable for compost production which can be used to replace chemical fertilizers in date palm plantations. Thus, abundance of date palm trees in the MENA and the Mediterranean region, can catalyze the development of biomass and biofuels sector in the region.

Reasons Why Greenhouse Ventilation is Essential

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The essential function of a greenhouse is to have the right environment for plants to grow. Thus, good greenhouse design is vital. Among the features of a greenhouse is ventilation.

The greenhouse needs excellent ventilation to create a balance in the indoor climate, maximizing the sun’s power while maintaining the air quality and optimal temperature to ensure that the plants will grow vigorously.

Why Greenhouse Ventilation is Essential

Whether operating a backyard greenhouse or a commercial greenhouse, keep in mind that air exchange is vital, not only for providing fresh air and carbon dioxide so your plants can photosynthesize. It will also regulate the indoor temperature in your greenhouse in all weather conditions.

A good ventilation layout is necessary

You need a good ventilation layout so you can effectively cool the greenhouse on a hot day. Use exhaust fans to blow the stale, hot air out of the structure. You also need intake shutters mounted opposite the exhaust system to take in the cooler fresh air.

For a commercial greenhouse, the exhaust fan system should change the air between one to three minutes in summer, which will keep a reasonable temperature inside the greenhouse. If you have a small greenhouse, the system will only need one minute.

Your commercial greenhouse should also have complementary equipment, such as variable-speed motors, motorized shutters and louvered fans. There should also be roof and side vents to keep a steady supply of fresh air and improve the cooling of the greenhouse.

If the summers are long and hot in your area, evaporative coolers could be the solution. They will add humidity, cooling, and air movement inside the greenhouse. You can use evaporative coolers together with the exhaust shutters.

Ventilation tips

It is essential to understand the needs of your specific crops so you can implement the right combination to boost their growth. Working with an expert in greenhouse structures will be beneficial in providing you with the perfect growing space under all weather conditions.

Cooling the greenhouse with wind and thermal buoyancy is one of the concepts that has been around for ages. The concept uses louvers or vents that open to allow excess heat to escape while cooler air from outside is allowed to enter.

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But when large polyethylene sheets became a popular covering for greenhouse roofs, placing the vents on the roof became a challenge. So engineers developed a system of using fans to draw outside air through louvers installed in one end of the structure and an exhaust fan system at the other end. The ventilation system using this method uses thermostatic control.

Hoop style greenhouses are more effective in providing ventilation using roll-up sides. But greenhouses with roof and side vents are more effective when there is enough space as the vents should be large enough to allow for good air movement. Many manufacturers are producing open-roof greenhouses. You can easily control the roof’s opening to maximize heat and cool air entry as needed.

Working with an expert greenhouse manufacturer will ensure that the structure will fit the crops you want to grow and maximize all the design features according to your location.