Hi.  We are moving to California soon to look after my uncle's business.  I have started searching for our new home.  I have 3 on my list.  Now I need your help about our purchase.  Do you happen to know a reliable company that offers a long term-fixed mortgage?  I really need recommendations.  Thanks for your time.

Hello farmers,am new here. Have raised 102 broilers with 27 mortality(sad),I wish to learn more on broiler and layers. Thank you

my birds made 19wks yesterday, they are not laying yet but i started adding egg booster in their drinking water. Is it right? Ur veiws will educate us all. Tanx.

is it proper to give lasota to pullets beyond 20wks of age. The last administration was @ 6wks of age.

pls, experts in the house i need to hear from u, i
have 51 brown pullets @ 131 days (about
19wks) old, i feed them 96grms/bird/day, yet
some still weigh bellow 1400grms. Pls is this
normal? How much longer will it take them to
start laying?

Hello everyone,

I am new here.

I am setting up a day old chick to point of lay and a broiler operation. I will appreciate all the help I can get. Also needing startup supplies in Nasarawa State.
Glad to be here

Hi every one am new and I need informations on everything about poultry Fram

Hello everyone! Please I want to know how many bags of feeds are 100 broilers suppose to finish in 6wks at most 8wks and what should be their expected weights? Any tips on healthy and fast growing of the chickens is welcome. I heard that there's a special injection that makes them grow faster and heavier, is it true?

Hello everyone! Please I want to know how many bags of feeds are 100 broilers suppose to finish in 6wks at most 8wks and what should be their expected weights? Any tips on healthy and fast growing of the chickens is welcome. I heard that there's a special injection that makes them grow faster and heavier, is it true?

Hello everyone! Please I want to know how many bags of feeds are 100 broilers suppose to finish in 6wks at most 8wks and what should be their expected weights? Any tips on healthy and fast growing of the chickens is welcome. I heard that there's a special injection that makes them grow faster and heavier, is it true?

POST DELETED BY ADMIN- SPAM

Hello every one my name is Ruth , I am new and I intend to start up a poultry farm and I am here to gain knowledge and also share the little that I know. Thank you. 

First, I'm from the Philippines and a beginner with regards to farming. Our family currently own a small piece of farm land. In connection with this, I want to take advantage of our land and I was thinking to breed some farm animals like cow, goat or chickens.  Its good that I'm able to grab this opportunity to learn from here.

Introduction
Immodest dresses are designed to cause men to lust and to draw attention to the body. The way you dress reveals your mindset. It is easier to take a stance against murder, rape, cheating etc, but it is harder to take a stance against the evils majority have come to accept. Evils like immodest dressing, ignoring the flaws of celebrities (celebrity worship) etc. This is because you risk being rejected and mocked by majority. But mind you, no political party, celebrity etc should be given allegiance that is due to God alone. If you fail to stand against evil in public/private places, you are directly rejecting Christ. True Christians are supposed to be Christ’s ambassadors on earth. Below are 6 reasons why a heavenly conscious girl/lady must not dress immodestly.

1.      God want men to control their thought: Matt 5:27-29 - “You have heard that it was said by them of old time, you shall not commit adultery:  28. But I say unto you, that whosoever looks on a woman to lust after her has committed adultery with her already in his heart.”  How does it concern you? Read on.

2.      God don’t want you to cause others to sin, if you disobey, there are consequences: Matt 18:6-8 “If anyone causes one of these little ones – those who believe in me – to stumble (sin), it will be better for them to have a large millstone hung round their neck and to be drowned in the depth of the sea. 7. Woe to the world because of the things that cause people to stumble, such things must come, but woe to the person through whom they come! 8. For if your hand or your foot causes you to stumble, cut it off and throw it away…” 

When you lead men to sin against God by the way you dress (or by any other means), there are severe consequences involve. So you can’t just say that it doesn’t concern you.

3.      God wants true Christians to dress modestly: 1 Tim 2:9-10 “I also want the women to dress modestly, with decency and propriety, adorning themselves not with elaborate hairstyles or gold or pearls or expensive clothes, 10. But with good deeds, appropriate for women who profess to worship God.” 

4.      Your body belongs to God and you must use it for His glory, not as an object of lust: Rom 12:1 “ I beseech you therefore, brethren, that you present your bodies as a living sacrifice, holy, and pleasing to God – this is your true and proper worship. 2. Do not conform to the pattern of this world, but be transformed by the renewing of your mind. Then you will be able to test and approve what God’s will is – his good, pleasing and perfect will.”

5.      If you are not part of the solution, you are part of the problem: Matt 12:30 “He that is not with me is against me; and he that does not gather with me scatters.” Ask yourself: “If I dress immodestly, how do I help gather people to Christ?” When men look at you, they should be seeing Christ in you, not your exposed body.

6.      Why will some people still insist that nothing is wrong with immodest dressing? Some people will label black as white and evil as good. Some people even regard immodest dressing as modest. When you believe that an evil is good, it eventually appear to be good in your eyes. 2 Thessalonians 2:10-12 “…They perish because they refuse to love the truth and so be saved. 11. For this reason God send them a powerful delusion to believe a lie 12. And so that all will be condemned who have not believe the truth but have delighted in wickedness.” It is a well-known fact that immodesty lead men to sin. Therefore immodesty is a great wickedness.

What Really is Modest Dressing?
If you have a clean heart, you’ll agree with me that a modest dress will meet the following requirements:

1.      Not too tight: In case you don’t know, prostitutes wear tight fitting clothes to reveal their shape and attract customers. But it is very unfortunate that most ‘christian ladies’ are doing the same.

2.      It doesn’t expose your nakedness: Nakedness here include your thighs, breast, stomach etc. A modest skirt goes down below the knees such that even when you sit or bend to sweep, your thighs won’t be exposed. A modest top doesn’t expose your stomach, ampit or cleavage, even when you raise your hands up in worship.

Conclusion
Do you condemn fornication but approve all those emotions and behaviors that lead to fornication (indecent dressing, kissing, pecking, hugging, fondling etc)? If yes, how are you different from the Pharisees who will condemn murder but ignore anger that leads to murder (Matt 5:21-26)?

How do we take a stand against immodesty? The same way we take a stand against rape, child abuse, ungodliness and theft. Shun immodesty and ungodly fashion (2 Cor. 6:14). Expose and rebuke immodesty. Eph 5:11-13 – “And have no fellowship with the unfruitful works of darkness, but rather reprove them. 12. For it is a shame even to speak of those things which are done of them in secret.   13 But all things that are reproved are made manifest by the light:  for whatsoever doth make manifest is light.”

You will dress modestly if your heart is inclined towards God. You will dress immodestly when your heart is inclined towards self. You’ll do this with little or no regard for the consequencies to yourself or others.

Note: Immodesty is not the only sin that can lead you to hell. By constantly STUDYING the bible, you’ll renew your mind and discover the will of God for your life (Rom 12:2). The conclusion of the whole matter is repentance. Make up your mind to repent from all your evil ways and follow Christ.

Hi, I'm a Nigerian based in Cameroun, I need tips on how to run a successful broiler farm. Thanks

Several cost effective methods can be used for the cultivation of Azolla as a livestock feed. The one described here was developed by India’s Natural Resources Development Project (NARDEP) and reported by agriculaturalnetwork.org:
http://www.agriculturesnetwork.org/magaz...stock-feed

Much of the information presented below is from NARDEP and the agriculaturalnetwork.org link listed above. The method is also documented in the following publication:
Kamalasanana Pillai, P, S. Premalatha, S. & Rajamony, S. 2001. Azolla – a sustainable feed substitute for livestock. LEISA India, Volume 4 number 1, March 2002.

NARDEP’s cultivation method
NARDEP therefore developed a method for cultivating Azolla that is easy and economical for livestock farmers. One of its attractions is that the dung produced by livestock is used to help fertilize the Azolla plants which, in turn, provide nutrition for the livestock.

• A water body is made, preferably under the shade of a tree, with the help of a silpauline sheet. Silpauline is a polythene tarpaulin which is resistant to the ultra violet radiation in sunlight. A pit of 2 x 2 x 0.2 m is dug as a first step.
• All corners of the pit should be at the same level so that a uniform water level can be maintained. The pit is covered with plastic gunnies to prevent the roots of the nearby trees piercing the silpauline sheet, which is spread over the plastic gunnies.
• About 10 – 15 kg of sieved fertile soil is uniformly spread over the silpauline sheet. Slurry made of 2 kg cow dung and 30 g of Super Phosphate mixed in 10 litres of water, is poured onto the sheet. More water is poured on to raise the water level to about 10 cm.
• About 0.5 – 1 kg of fresh and pure culture of Azolla is placed in the water. This will grow rapidly and fill the pit within 10 – 15 days. From then on, 500 – 600 g of Azollacan be harvested daily. A mixture of 20 g of Super Phosphate and about 1 kg of cow dung should be added once every 5 days in order to maintain rapid multiplication of the Azolla and to maintain the daily yield of 500 g.
• A micronutrient mix containing magnesium, iron, copper, sulphur can also be added at weekly intervals to enhance the mineral content of Azolla.

Summary of NARDEP’s method of Azolla production
• It is important to keep Azolla at the rapid multiplication growth phase with the minimum doubling time. Therefore biomass (around 200 g per square meter) should be removed every day or on alternate days to avoid overcrowding.
• Periodic application of cow-dung slurry, super phosphate and other macro and micronutrients except nitrogen, will keep the fern multiplying rapidly.
• The temperature should be kept below 25°C. If the temperature goes up the light intensity should be reduced by providing shade. If possible, it is best to place the production unit where it is shady.
• The pH should be tested periodically and should be maintained between 5.5 and 7.
• About 5 kg of bed soil should be replaced with fresh soil, once in 30 days, to avoid nitrogen build up and prevent micro-nutrient deficiency.
• 25 to 30 percent of the water also needs to be replaced with fresh water, once every 10 days, to prevent nitrogen build up in the bed.
• The bed should be cleaned, the water and soil replaced and new Azolla inoculated once every six months.
• A fresh bed has to be prepared and inoculated with pure culture of Azolla, when contaminated by pest and diseases.
• The Azolla should be washed in fresh water before use to remove the smell of cow dung.

Harvesting and preparing Azolla as livestock feed
• Harvest the floating Azolla plants using a plastic tray having holes of 1 cm2 mesh size to drain the water.
• Wash the Azolla to get rid of the cow dung smell. Washing also helps in separating the small plants which drain out of the tray. The plants along with water in the bucket can be poured back into the original bed.
• For use as a livestock feed, the fresh Azolla should be mixed with commercial feed in 1:1 ratio to feed livestock. After a fortnight of feeding on Azolla mixed with concentrate, livestock may be fed with Azolla without added concentrate.
• For poultry, Azolla can be fed to egg layers as well as broilers.
• In case of severe pest attack the best option is to empty the entire bed and lay out a fresh bed in a different location.

Cost
The cost of producing Azolla using NARDEPS’ method is less than Rs 0.65 per kilogram (approximately 0.015 US dollars, or 1½ cents per kg).

Trying it out
The following article by Anita Ingeval from the article Azolla: a sustainable feed for livestock illustrates the successful use of Azolla as a livestock feed:
“After reading the article on Azolla in the March 2002 issue of the LEISA India, the LEISA India columnist and organic farmer Mr. Narayan Reddy decided to test the production of Azolla on his farm. As his grandchildren were visiting, they were set to dig the first bed of 2 x 3 x 0.15-0.2 m.

To simplify the construction, Mr. Reddy made some adaptations: He lined the bed with a simple plastic sheet, fixed the sheet with the dug out soil together with some concrete along the edges, taking care that the plastic above the water was well covered – as otherwise the sun will rapidly deteriorate the plastic. After fixing the plastic, about 2 – 3 cm of stone free soil was carefully put back in the bottom of the bed which was filled with water.

The water depth is important; too little water will allow the Azolla roots to grow into the mud, making it difficult to harvest. Too much water will reduce the production as the roots do not reach close enough to the nutrients at the bottom.

After filling the bed, Mr. Reddy went off to the closest university to ask for some Azolla plants and put them in the water. He added 0.5 – 1 kg of neem cake to prevent possible pest problems and every three weeks he adds slurry of cow dung and water (10 kg fresh cow dung).
One and a half years later Mr. Reddy is enthusiastic about Azolla. He feeds it to his cows and chickens and after getting used to the Azolla (in the beginning he mixed the Azolla with concentrate) the animals love it. He has had to fence the bed to keep them out. He also uses the Azolla for salads, after washing it in fresh water and removing the root.

He empties and cleans the bed once every half year and starts it up again with some plants, neem cake and cow dung. When the temperatures soar in the summer, the bed is covered with a roof of loose palm leaves to give some shade and reduce light and temperature. However, the use of a simple plastic sheet for lining makes the bed very vulnerable – it can easily be damaged during harvesting or cleaning and Mr. Reddy therefore makes sure that he carries out these tasks himself.
With this simple system, the only costs are for the plastic sheet and for 2 kg of neem cake per year – plus his own labour.”
 
 
Azolla feed pellets
Azolla Foundation Associate Dr Kamalasanan Pillai at VKNARDEP in India has developed the technology to produce livestock feed pellets from Azolla:

“There is an ever increasing demand for milk, meat and egg. The production often fails to cope up with demand with the result the prices of livestock production are going up. 70–80% of the cost of production of livestock is feed cost, and this is increasing on an average 10-15% per annum. Protein part of livestock feed is the costliest part. There is a global deficit of plant protein sources, for feed production for livestock, which act as a major source of protein for humans. This is made good by chemical protein equivalents like urea, anabolic boosters like steroids which affect both the health and longevity of livestock and human consumers.

We have developed Azolla bio-feed technology to solve this problem. Azolla is a floating fern with a blue green algae endosymbiont in it, which fix atmospheric Nitrogen and produce a variety of protein and protein compounds and is No.1 in biomass 1000 MT/Hectare/year* and No.1 in protein 25–30 MT protein/Hectare/year.

The poor shelf life of green Azolla was a major shortcoming solved by Azolla based feed pellet technology. The Azolla based pellet is cheaper by 10–15%. Moreover, it improves the quantity and quality of milk, meat etc. by 5–10% production. The technology is eco-friendly, renewable, economically feasible and is a boon to the farming community.”
(* metric tonnes per hectare per year)

VKNARDEP are based in Vivekanandapuram Kanyakumari,Tamil Nadu, in India. They can be contacted at:
Secretary, Vivekananda Kendra-NARDEP
Vivekanandapuram Kanyakumari
Pin-629702
India
Phone:04652-246296
email: vknardep@gmail.com

by DR YUSOF BASIRON on Apr 29, 2013

Farming with animals is called draft animal power (DAP). It is an ancient practice but it can still be use today by small scale farmers. If you look around in many places, you’ll notice that majority of farmers practiced small scale farming and a lot of them employ manual labor, especially in poor countries. A work animal can do the work of 10 men… DAP is often more economical than machineries and vehicles that cost millions of naira. The value of machineries depreciates while that of animals appreciates as they give birth. DAP is not powered by fosil fuel. It depends on bioenergy for its creation, maintenance and functioning.

Apart from carrying loads, animals can be use to plough. This is easily employed in fields without roots of trees and shrubs. So fallow period of fields should be short. 2 oxen can plough 8 hactare of land in 32 days. That is 0.25ha per day. 2 bullock working 6hrs/day can plough an acre in 2.75 days. One buffalo working 8hrs/day can plough0.27-0.4ha of paddy land or 0.4-0.53ha of non-irrigated land. Each oxen will need 2000kg DM/yr in feed or 5.5kg DM/day. Green grass can be fed at 5-7kg/day and increased to 10kg/day when work is much. Small amount of supplement should also be given. They include brans, oil cakes, pulses, rice hull, molasses etc.

Research workers recommends that land be ploughed 6-7 times before sowing. But some farmers plough 4-5 times.
The true reason for poor penetration of plough is not the weight of the plough, but  worn or incorrectly aligned shares, tines etc, bad design. Higher angle of pull reduce work load on the animal and reduce the work the implement can do, but the animal will not get exhausted easily.

For low draught operations like weeding and planting, using single animal with well-designed harnesses will double the work output.

Load Carrying Capacity: A load weighing 800-1000kg on a wooden wheel can be drawn by a buffalo over 24km in a working day.  A buffalo can raise enough water to irrigate 0.73ha of paddy in 4 hours.
As a general rule, provided all other factors are favorable, bovines (i.e. cattle and buffaloes) should be able to provide a sustainable draught force of 10-12% of their body weight, while equines (horses, donkeys and mules) and camels will provide 12-14%.

Work Day: Average work day if 4-5 hrs for cows, 6hrs for buffaloes. Animals used for ploughing follows a pattern of 6-8 days of ploughing and 2 days of rest. A bullock in full time ploughing (i.e. maximum heavy labor) typically work for 163 days per year. 

Harnesses: Yorks are used for bovines and collar harnesses with breast strap for equines. Either single yokes or collar harnesses can be used on single oxen. Double shoulder yoke is easy and cheap to make but is inefficient and causes sores and injuries. Shaping the yoke to give a large contact area between the yoke, neck and shoulder with padding if necessary, inimizes pressure and enables the animal to exert more force without pain and improve the power output.
Full or split collar harnesses can be used effectively with oxen, buffalo and donkeys.

Azolla has enormous potential as a livestock feed due to:

1 Its high content in proteins, essential amino acids, vitamins (vitamin A, vitamin B12, Beta Carotene), growth promoter intermediaries and minerals.
2 Its ability to proliferate without inorganic nitrogen fertilization.
3 Its high rate of growth in water without the need to displace existing crops or natural ecological systems.

It has been used for many years throughout Asia and parts of Africa to feed pigs, ducks, chickens, cattle, fish, sheep and goats and rabbits.
Click here for details about cultivating Azolla for livestock feed and its profitability when used as a  livestock feed.
 
Suitability of Azolla as a livestock feed
Green plants have long been recognized as the cheapest and most abundant potential source of proteins because of their ability to synthesize amino acids from a wide range of virtually unlimited and readily available primary materials (Fasuyi & Aletor, 2005)
Azolla is very rich in proteins, essential amino acids, vitamins (vitamin A, vitamin B12, Beta Carotene), growth promoter intermediaries and minerals including calcium, phosphorous, potassium, ferrous, copper, magnesium.  On a dry weight basis, Azollahas 25-35% protein content, 10-15% mineral content, and 7-10% comprising a combination of amino acids, bio-active substances and biopolymers (Kamalasananaet al., 2002). Azolla’s carbohydrate and oil content is very low.

Azolla is also rich in iron (1000–8600 ppm dry weight), copper (3–210 ppm dry weight) manganese (120–2700 ppm dry weight), vitamin A (300–600 ppm dry weight.), vitamin A (300–600 ppm dry weigh), chlorophyll and carotenes. It contains 4.8–6.7% dry weight crude fat, with 6.1–7.7% and 12.8– 26.4% total fat for the polyunsaturated acids omega 3 and omega 6 (Paoletti et al., 1987).
Azolla meal contains 25.78% crude protein, 15.71% crude fiber, 3.47% ether extract, 15.76% ash and 30.08% nitrogen free extract on the air-dry basis (Basak et al., 2002).  In addition, aquatic plant species including Azolla do not to accumulate secondary plant compounds and therefore has a greater potential than tree leaves to source protein for monogastric animals.
Becerra et al. (1995), Lumpkin & Plucknett (1982) and Van Hove & López (1983) all concluded that Azolla is the most promising aquatic plant for livestock feed due to its ease of cultivation, productivity and nutritive value.  Azolla’s use as a feed for fish, swine and poultry was also tested and recommended by Alcantara & Querubin (1985) and Tran & Dao (1979) reported that one hectare of Azolla can produce 540-720 kg of protein per month.

Azolla’s composition therefore makes it one of the most economic and efficient feed substitutes for livestock, particularly as can be easily digested by livestock due to its high protein and low lignin content.


Here are some examples.

   
Left: Farmer inoculating a rice paddy with Azolla. Right: Azolla growing between rice plants.


The ability of Azolla’s symbiont, Anabaena, to sequester atmospheric nitrogen has been used for thousands of years in the Far East, where Azolla is extensively grown in rice paddies to increase rice production by more than to 50%.

Rice is an enormously important staple in many tropical and temperate regions of the world. Billions of people rely on the crop to live and hundreds of millions are now threatened by food shortages that are increasing each year.

World rice production was approximately 645 million tonnes in 2007. At least 114 countries grow rice and more than 50 have an annual production of 100,000 tonnes or more. Asian farmers produce about 90% of the total, with two countries, China and India, growing more than half the total crop.
Nitrogen is the single most limiting factor in rice cultivation, strongly affecting the crop yield. Azolla substantially increases the amount of nitrogen fertilizer available to growing rice and it is has been used for thousands of years as a ‘green’ nitrogen fertilizer to increase rice production.
Research into Azolla’s use in rice production has therefore grown over the past years, including the development of new hybrids.

Videos of Azolla‘s use to increase rice production are shown here.

Azolla’s increase in rice productivity
Less that 5% of the nitrogen sequestered by Azolla is available immediately to the growing rice plants. The remaining 95% remains in the Azolla’s biomass until the plant dies. As the plant decomposes, its organic nitrogen is rapidly mineralized and released as ammonia, which then becomes available as a biofertilizer for the growing rice plants.
Various techniques have therefore been developed to maximize Azolla’s nitrogen fertilization, with the result that Azolla now has enormous potential to increase rice production worldwide and hence alleviate food shortages.

These include methods to increase the availability of the nitrogen assimilated byAzolla-Anabaena to the growing rice plants.

In Tanzania, Wagner (1996) applied Azolla nilotica in various trials as an intercrop and obtained increases of up to 103% in rice grain yield.

Experiments at the University of California at Davis showed that Azolla increased rice yields by 112% over unfertilized controls when applied as a monocrop during the fallow season, by just 23% when applied as an intercrop with rice. However, the amount increased by 216% when Azolla was applied both as a monocrop and an intercrop (Peters, 1978).

Azolla’s nitrogen release into water
Most of the nitrogen fixed becomes available to rice only after the Azolla has decomposed, although a small amount of ammonium is released into the water byAzolla during growth (Watanabe, 1984)
This was confirmed by Chung-Chu (1984), who determined that only 3 to 4% of the total nitrogen fixed by Azolla is excreted into the water medium during its growth.

During decomposition, organic nitrogen is mineralized rapidly during the first two weeks and then at a more gradual rate (Watanabe, 1984). Nitrogen is released mainly in the form of ammonium. Ammonium-nitrogen released was found to stabilize at about 1 mg ammonium-N g-1 of fresh Azolla, which was 26-28% of the total nitrogen content of Azolla (Tung & Shen, 1985).

Azolla’s incorporation of nitrogen into soil
Incorporation of Azolla into the soil improves the release of nitrogen (Tung & Shen, 1985). If Azolla is grown as a monocrop and the field should be drained several days in advance of incorporation. The last mat should be incorporated and the field kept drained for 4 or 5 days before transplanting rice in order to speed decomposition (Lumpkin, 1987a).

Azolla’s use as an intercrop
Azolla incorporated 78 days after transplanting rice was shown to contribute a greater amount of nitrogen to rice grain than was contributed by earlier incorporation (30-53 days after transplanting) (Ito & Watanabe, 1985). Since it has been found that the optimal stocking density for Azolla, with respect to area-specific nitrogenase activity, is approximately 50 to 100 g dry weight m-2 (Hechler & Dawson, 1995), nitrogen inputs may be best maximized by frequent but partial incorporations of Azolla.

Other benefits of incorporating Azolla in rice cultivation
As well as its nitrogen biofertilization, Azolla provides a variety of benefits for rice production and grows in a way that is complementary to rice cultivation:

[1] The thick Azolla mat in rice fields suppresses weeds.
[2] Since Azolla floats at the water surface, it does compete with rice for light and space.
[3] In most climates, Azolla grows best under a partial shade of vegetation which is provided by the rice canopy during early and intermediate stages of growth
[4] When the rice approaches maturity, Azolla begins to die and decompose due to low light intensities under the canopy and a depletion of nutrients, thus releasing its nutrients into the water.
[5] Because Azolla decomposes rapidly, its nitrogen, phosphorus and other nutrients are rapidly released into the water and made available for uptake by rice during grain development.
[6] Azolla has a greater ability than rice to accumulate potassium in its tissues in low-potassium environments, providing rice with potassium after Azolla’s decomposition
[7] In contrast with chemical nitrogenous fertilizers, Azolla has various positive long-term effects, including the improvement of soil fertility by increasing total nitrogen, organic carbon, plus phosphorus, potassium, other nutrients and organic matter.
[8] If chemical nitrogenous fertilizers are applied, the presence of an Azolla mat reduces ammonia volatilization that would normally occur.
[9] When grown in a rice field, Azolla reduces the ammonia volatilization that occurs following the application of inorganic nitrogen fertilizers by 20% to 50%. This is due to the fact that the Azolla cover reduces light penetration into the floodwater, thus hindering the rise of pH which normally stimulates ammonia volatilization in an Azolla-free rice field (Watanabe & Liu, 1992).