Trevor
Craig
Energy
Science 110
Crop
Intensification, Forests, & Biomass Energy Today, 12
10/2/11
This lecture was about the green
revolution and biomass, primarily being wood, usage throughout the world. When
we grow plants and harvest them we take a little of the earth’s nutrients.
Coffee yields 2000 kg/ha and has 293 kg/ha of potassium within them from the
soil, after prolong use of the same crop the soil begins to be deficient of the
nutrients which the crop needs. This is the biggest problem for nitrogen,
potassium, and phosphorous.
Not all of the ground in the world can
be used for planting crops, where we can plant crops is limited by many things
like, drought, mineral stress, shallow depth, water excess, and permafrost,
leaving only about 11% of the world’s land to be able to be used for crop
growing without serious limitations. Increasing the percentage of land without
major limitations was one of the ideas of the green revolution.
During the green revolution we saw an
increase of crop yields, between the years 1960’s and 1980’s. One of the major reasons
we have seen crops increase is because of the use of fertilizer, especially the
fertilizer nitrogen. In 1960 the amount of nitrogen we were using was about 2
million tons, and then in 1980 it was 20 million tons, and finally in 1990 it
was at 40 million tons of nitrogen. Nitrogen helps crops grow but only to a
certain point, crops seem to be helped when using nitrogen up to 200 kg N/ha,
then they start to level out in growth or actually decrease. With this increase
in agriculture yield during the green revolution there was also an increase in
meat production between the years 1950 and 2000, where it increased 5 fold.
Depending on how we grow the plants
determines how much nutrition is used and how much is left in the soil. Slash
and burn technique supplies food for approximately 40 million people but is not
a very effective or ecofriendly technique. The most used cropping system is
irrigated continuous lowland using only 24 million ha. and providing food for 1800
million people, where slash and burn technique used 1,035 million ha. and
provided for 40 million people.
Trees are extremely important to society
and have been used as a primary source of fuel and building materials for over
5000 years. Today 40% of the world often uses biomass to heat their homes and
cook their meals. The use of biomass as our primary fuel source has gone down
to almost 0 but with rising oil prices we could use more biomass for energy,
like we used to, to help offset the rising price of oil.
Per
capita- Per
unit of population; per person.
Fertilizer-
Any of a large number of natural and synthetic materials, including manure and
nitrogen, phosphorus, and potassium compounds, spread on or worked into soil to
increase its capacity to support plant growth.
ENSC110 Craig Crop Intesification
No comments:
Post a Comment
Write things here...