This is the VOA Special English Agriculture Report.
Advice on how much fertilizer to use will soon be just a phone call away for rice farmers in the Philippines.
The Philippine Department of Agriculture and the International Rice Research Institute plan to launch a free service next month.
Farmers will call a number and a recorded voice will ask them simple questions in Tagalog or other languages including English.
RECORDED VOICE: "Welcome. This is the nutrient manager for rice. Answer a statement by pressing the appropriate number on your phone."
For example, to get fertilizer guidelines for the wet season, they press one. For the dry season, they press two.
Farmers will be asked about the size of their field and how many bags of rice it produced last year.
What about natural sources of fertilizer? Does the farmer return rice straw to the field? Is the field near a lake or river that floods, or in a low area collecting soil and other material from nearby hills?
About ten minutes later the farmer will get a text message. The message will advise what kind of fertilizer to use and how much. The grower will also get suggestions about when to plant and harvest the rice.
Roland Buresh at the International Rice Research Institute helped developed the system. Mr. Buresh says fertilizer represents about one-fifth of the cost of inputs for rice production.
He says the service could help farmers in the Philippines increase their yields and their profits.
ROLAND BURESH: "If we in a year can be reaching just five thousand farmers and their fields can be increasing the yield by half a ton per hectare, we could be looking at profitabilities for those farmers in the range of half a million dollars."
Danielle Nierenberg at the Worldwatch Institute, an environmental research group, says the system could also help reduce pollution.
环境研究组织世界观察研究所(Worldwatch Institute)的丹尼尔·尼伦伯格（Danielle Nierenberg）表示，该系统还可以帮助减少污染。
DANIELLE NIERENBERG: "In the Philippines and all over Asia, fertilizer has been overused and misused because no one explains to them how much they need or how to use it."
The technology could also be copied for crops in other places. Danielle Nierenberg has been traveling across sub-Saharan Africa. She says the cost of a cell phone there is low enough that most farmers have their own or borrow someone else's.
In Zambia, for example, farmers without bank accounts can use their phones to buy seeds and fertilizers. They can also get information on how much their crop is selling for in city markets.
DANIELLE NIERENBERG: "They can decide whether they want to travel all the way from their village to the city, because sometimes farmers get there and prices are too low."