Agriculture Reference
In-Depth Information
T A B L E 10.2. Rainfall Needed for Crops
Crop
Minimum
Average
Chickpea
150 mm
150 - 200 mm
Sorghum
280 mm
600 - 1000 mm
Peanut
300 mm
500 - 600 mm
Barley
400 mm
400 - 450 mm
Maize
500 mm
1200 - 1500 mm
Wheat
500 mm
570 - 600 mm
Rice
500 mm rainfed
.1500 mm irrigated
Source: From Ref. 1.
monthly totals. This has a large effect on farming practices. A farmer in southwest
India can expect the monsoon rains to start around June 1. It may be as much as 2
weeks earlier or later, but this is the average. This means that farmers must have
their seed purchased, fields tilled, and rice ready to transplant before this date. If a
farmer is not ready, tillage and transplanting rice become more difficult as the
monsoon goes on.
Consider the calendar of farming operations that farmers must follow in Ohio,
Zimbabwe, and India by consulting the rainfall charts in Figure 10.4. Even though
the total yearly rainfall of each location is similar, the distribution of the rain dictates
totally different farming calendars. A farmer in Bulawayo, Zimbabwe, will prepare
planting materials in October, but an Indian farmer in Patna, India, will be harvesting
rice in October. Planting for this farmer in north India will be in October for wheat and
in late May for rice. The wheat will be planted just after rice harvest. A farmer in Ohio
is blessed with precipitation all year long. Planting of summer crops will be done in
May with harvest in October or November. Some crops, such as winter wheat, will
be planted in late September but won't be harvested until after the winter passes and
the crop matures in July the following year. The even distribution of precipitation
throughout the year makes agriculture high yielding and less uncertain than in
Zimbabwe or India.
Rainfall is considered separately from irrigation in this chapter because most
farmers depend solely on rain for their crops. Installation of an irrigation system and
use of irrigation water requires a very different set of conditions, and this topic is con-
sidered in a separate section.
10.6
ROADS
Roads are possibly the most important input for a commercial farmer. If there are
no good roads to an area, farmers cannot get their product to markets. They also
cannot get needed fertilizer and seeds to their farm. In areas where the government
is not able to adequately maintain roads, it is common for farmers to collectively do
periodic maintenance before planting and harvest.
