This course will cover the agricultural and urban water quality issues in Florida, their bases, land and nutrient management strategies, and the science and policy behind the best management practices (BMPs). Students will learn to evaluate BMP research and analyze its role in determining practices and policies that protect water quality.
The Big Picture - The Value of Agriculture
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Do curso por University of Florida
Gestão Sustentável na Agricultura
47 classificações
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Water Quality Issues and Regulations
In week 2, we will take a look at the big picture and some interesting examples, discuss the value of agriculture, and cover the im
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George J. Hochmuth, Ph.D.Professor
Urban and Agricultural Environmental Sciences
Welcome everybody. This is Lecture 2 of Week 2.
As I told you before, I wanted to dig down a little bit deeper in studying sort of
the general issues with regard to agriculture and water quality.
And I want to spend a little time talking about agriculture in this state, because I
think it's very interesting to look at the kinds of enterprises, the diversity of
enterprises that we have in the state. And sort of sit back and think about the
kinds of water quality issues that might be associated with those practices if
those farmers are not following good, best management practices.
Florida, as I mentioned before located in the southeastern part of, of the United
States, is not a large state as it goes, but it's and it's, and it's not a small
state either. One of the important attributes that
Florida has is a long coast line and this is good for our tourist industry.
But also, it, it, it can on the other hand be a challenge for managing water quality.
Because what we're doing on the land of this state can eventually end up and
impact the water quality of our coastal areas, and those are the areas that people
like to come as tourists. Florida agriculture, as I mentioned
before, is a very large economic force in this state.
For example, all of our commodities agriculture commodities in 2008, the
recent, most recent data amounted to about a 7 billion dollar amount of cash receipts
to the farm. And if you look down the list you'll
quickly realize that it's the horticulture crops.
Citrus, vegetables, foliage, and floriculture all added together are the
driving force of our agriculture industry. And sure, we have other enterprises that
are important parts of our agriculture industry as well, and those are the animal
agriculture. So, many people probably recognize when
you say, citrus and maybe tomatoes as being associated with Florida.
But maybe not many people recognize that Florida has a major poultry industry and a
major dairy industry. Most people think of dairy and as in the
northern part, Pennsylvania, New York, and Wisconsin.
But Florida has a major dairy Industry. For agriculture, it is important for two
reasons. One is at certain times of the year, in
the winter time, this state produces a lot of food that this country and others
enjoy. So, it's very important to our country.
And the Florida agriculture is important to the state.
It's the economic driver. And I'll mention in a second, the food we
produce in the state also stays in this state, to a large degree, because we have
a lot of people in the state that enjoy that same orange juice as someone in
Pennsylvania may. But what is it about Florida that makes
this all possible? I think it's encapsulated in a graph like
this. These are the minimum temperature
isotherms for January in this state. And the thing that jumps out to you are
the numbers, particularly if you're from Minnesota, how warm it is in January in
the state of Florida, particularly along the coast.
And if you remember, we showed some pictures of the coastal area and the
urbanization in the coastal area and how urbanization and agriculture compete for
that same warm land. And around the coastal area where you have
those narrow bands of warm weather, that's exactly where agriculture has flourished
in this state, because those are the areas that you can produce crops in the winter
time, with the minimum chance of having frosts or freezes.
But there also the areas that people like to live in this state.
And so, that's where a lot of our large metropolitan areas are as well.
So, Florida is known primarily for a producer of horticulture crops, in the,
what I will call out of season, the winter production cycle.
Tropical and ornamental plants are very important in this state.
Most any one that has purchased a fern or some other potted tropical plant for their
home, likely that plant was produced in a greenhouse somewhere in Florida.
Florida also is very important to the animal industry, particularly the cattle
industry, because we can graze grass in certain parts, the warmer parts of this
state, year-round. So, that's very economical for a farmer
not to have to invest a large amount of resources to produce and, and purchase hay
for feeding the cattle. And I mentioned also that Florida
agriculture is strong partly because we have good markets available to our
farmers. And if you think about the metropolitan
areas up and down the East Coast of this country you come to the conclusion that
there are lots and lots of people that enjoy Florida agriculture.
If you look at the energy situation and ask the question, how much does it cost to
ship vegetables from California, another vegetable, major vegetable producing area
in this country, to the East Coast markets versus getting those same vegetables from
Florida and you can see the economies favor agriculture production in Florida.
So, agriculture is probably here for a long, long time.
What are some of these agriculture commodities in the state?
I like to start with vegetables because that's what I've worked with most of my
career. This is a small collection collage of
various vegetable crops that are important in this crop in this state.
Here's tomatoes produced on plastic mulch, raised beds with plastic covered mulch.
We'll talk about that later on in the course, about how plastic mulch has become
a very important part of a nutrient and water management best management practice.
Also, our crops are irrigated. Here's sweet corn with center pivot
irrigations in the state of Florida. Pretty soon, we're going to talk a little
bit about soils and how they relate to environmental impact and water quality.
Most of our soils in Florida are very sandy in nature.
We produce a lot of crops on these sandy soils and we do it for lots of reasons.
But most notably, the sandy soils drain very well, unlike those soils that we
mentioned for the upper Midwest and the Mississippi watershed.
Florida soils are very sandy so water and nutrients can move through these soils
very easily and that's the, that's the challenge.
They're good, but also they're challenging because nutrients can move through them
and end up in our groundwater. So, these soils have to be managed very,
very carefully. Sandy soils warm up very fast in the
spring and they're very good for producing high quality crops.
Think about growing potatoes, for example, on sandy soils versus growing potatoes on
clay soils. Here's some more photos of vegetable
production. This particular one in the middle is a
small farmer that's using some best management practices that we will talk
about. Plastic mulch, for example, you might
notice the drip irrigation tubing in the center of this bed.
The cover crop and the rye wind breaks, that we'll talk about for preventing wind
erosion. The picture in the lower right is planting
celery on the organic soils in Lake Okeechobee.
These are the muck soils or the histosols, these are the soils that were drained so
that we could grow vegetables in that area of the state.
Now, Florida is urban, and along with that is the need for turf or lawns in, in your
landscape. And so as homes are built Florida has a
major sod industry growing the turf grasses that will soon end up in people's
front and backyards. Here's an example of a, of a sod farm in
Florida, large acreages of a particular variety of sod.
This sod will be cut in strips and taken to a home that is under construction and
laid on the ground to be the lawn for that for that home.
Maybe some of you know and realize that Florida is a major sugar cane state, the
leading sugar cane state. I've shown you some pictures here of sugar
cane growing in the field. During the harvesting process, prior to
harvesting, sugar cane is burned to get rid of the extra leaf material and make it
easier for the machines to go through and cut the cane.
The cane is then taken off to the sugar mill to be squeezed and the juices refined
to sugar. Sugar cane in the state has been largely
grown on the muck soils or the organic soils around Lake Okeechobee.
But those soils, because they are organic and we now have drained them and exposed
them to air are oxidizing, and the depth of the soil is declining, such that in
some areas, the muck soil is too shallow to successfully grow crops and sugar cane
is now starting to be grown on the sandy areas at the periphery of the Everglades
area. Livestock and hay crops are important.
We've already mentioned the poultry industry in the lower right-hand corner.
This is a manure storage facility at a poultry farm in north Florida, to put the,
the poultry manure out of the weather so that it's not, so the nutrients aren't
leached before the farmer has a chance to move that poultry manure onto a field for
use as fertilizer, for example. Example.
The other pictures show you cattle grazing in, in the state, the hay production that
goes along with our industry particularly in the northern part of the state.
And along with our animal industry comes this other sort of parallel challenge and
that's what to do with the animal wastes. And so, I've shown you some pictures here
of beef cattle. And also spreading manure on a farm in
preparation for planting the crop. And I also want to bring to your attention
that a role that agriculture plays even for the urban areas.
This is a waste-water treatment facility that produces biosolids and reclaimed
water, which can be used if treated properly on agriculture lands.
So, agriculture can provide a setting to help urban areas deal with the waste, the
increasing amounts of waste that are produced in these areas.
Here's one of our major crops growing on sandy soils in central Florida.
These are very deep, sandy soils. This is citrus.
These are orange trees. Most of the citrus crop in this state goes
to orange juice. And this is one of the groves in the
central part of the, of the state. But we also produced a lot of specialty
citrus. This particular video shows navel oranges.
We also grow a lot of grapefruit, tangerines, and specialty citrus that are
favored by everyone around the country. Florida is also one of the largest
producers of peanuts in the country. Our peanuts in Florida go for peanut
butter and for candies. And the University of Florida is a major
contributor to the variety development of these peanuts, because we need to grow
peanuts in our tropical, warm climate. Once the peanuts have been taken out of
the hull or the shell these shells can be used for cattle bedding.
Here's a picture of one of the challenges that we have in the state of Florida for
producing crops. You'll notice here that we have tomato
crops growing on plastic mulch. We'll talk about this later, but you might
notice the drip irrigation tubing to supply water and nutrients under the
plastic mulch to this crop. What you may also notice, here's a row not
doing quite as well as these. This row has not received any nitrogen
fertilizer. Our sandy soils are basically devoid of
large amounts of organic matter, and thus, nitrogen.
So, farmers have to add fertilizer, particularly nitrogen to these crops to
get them to perform properly and adequately to give the kinds of yield, and
the quality of the fruit production that farmers require.
In fact, fertilizers account for half of the world's food.
Said another way, half of the world's people would not be here if it were not
for fertilizers. Long ago, scientists and farmers, like in
the lower right-hand picture, figured out that you got very little crop if any crop
at all, particularly on sandy soils without fertilization.
So, fertilizer has been a very important factor to agriculture in a state like
Florida. Here, I show you a picture of some data
taken from that study that I just showed you in the previous picture.
Without nitrogen fertilizer, very little yield.
But it doesn't take much nitrogen added to get to the highest yield.
What else do you notice about this particular graph?
Well, I noticed that at about, between 140 and 200 pounds per acre of nitrogen, you
get maximum yield. What happens when I put more nitrogen on
in the hopes that more is better? It's not better, in fact, it's even worse.
Plants are adapted this way that, and our crops respond to a certain level of
nutrients. We call this the right rate of nitrogen
and we'll study this a little bit later on.
And so,f a farmer is looking for more yield by more fertilizer, they might run
into this situation which, which would be a negative impact on their profitability.
But this extra nitrogen that's going on out here and not returning a crop, the
question becomes where does that extra nitrogen end up if the crop is not using
it? Here's another shot of a tomato field
under plastic mulch, a little different kind of plastic mulch because these crops
are grown in the warm fall. But again, you see plots out here have,
have been fertilized, looks like they're growing well, probably producing a good
crop, versus parts of this field that have not been fertilized to an adequate,
adequate extent, low yields and probably very small fruits.
So, it doesn't take many of these kinds of studies to illustrate the importance of
fertilizer to agriculture in the state of Florida.
The question becomes, how do we manage those nutrients so that they benefit our
crops and our productivity and our good return on investment for the farm but do
not contribute negatively to the water quality if they get lost from the land
through leaching, or erosion? Besides fertilizer for our agriculture,
water is extremely important. You might say, well, why is that?
Florida is a humid state and gets lots of lots of water, rainfall.
And you would be right except that in many of our agriculture areas that rainfall may
not fall when the farm needs the water. And so, we supplement rainfall with
irrigation. And I'm showing you a picture here of
center pivot irrigation systems. In central and northern Florida, center
pivots, I think you might recall, the picture of the center pivot in operation
on a sweet corn field. These are very important irrigation
systems for agriculture. The challenge that we have with irrigation
systems like the center pivot, they're very efficient and very effective at
delivering water to the crop. But they also need to be managed and we'll
talk a little bit about irrigation management best management practices so
that the water delivered from these irrigation systems benefits the crop and
stays in the root zone and does not leach below the root zone as it would be the
case if we applied too much water. Because when it does in a sandy soil, it
can move mobile nutrients like nitrogen below the root zone and eventually into
our springs. Another innovation that 's been around for
several decades irrigation system is drip irrigation.
I've already showed you a small farmer in northern Florida using drip irrigation.
Drip irrigation is a system where we have a, a plastic, a polyethylene tube, that is
laid on the ground near the plant's base, and supplies water and nutrients.
The advantage of drip irrigation is that water and nutrients can be applied right
there at the plant, in the root zone, and not anywhere else, so that we can make
very efficient use of the water and the fertilizers that we apply to the crop.
And for many of our vegetable crops, drip irrigation is part of a best management
process for those crops. But like with fertilizer, we need to
manage water. Here are two pictures of over or excessive
irrigation. And you can see, when too much water is
applied, you can see in this top picture how some of the water is starting to erode
the soil and exit this field. If that happens, a situation like this can
occur, where water and some of the soil and the nutrients, particularly phosphorus
that's attached to those soil particles can move off of that site, and may end up
in a water body. So, water needs to be managed.
We'll talk about the concept of keeping nutrients and water in the root zone.
And right rate of fertilizer is important but right rate and right amount of water
is equally important, particularly on our sandy soils.
And when these nutrients get loose in the system and end up in our water body,
eutrophication can happen when things are not managed properly.
And, of course agriculture agriculture's farmers, do not want to lose soil or
nutrients or water because those represent dollars that are being invested in the
production of that crop and the return on investment of those inputs is less.
So, some take-homes from this particular lecture.
Hopefully, we've acknowledged that Florida obviously has a very, very important and
varied agriculture industry. It's very important to the economy of the
state. It produces a lot of good food that a lot
of people like to eat. Agriculture is critical to this state's
economy because it's large but also because it's a steady force in the
economy. You could count on agriculture to the, in
the economy. We also have taken a little bit of a
glimpse, and we'll look at it more but we've taken a glimpse at some of the
climate and soil challenges that the state has.
Rainfall is heavy and not very predictable.
Soils that are very sandy. They're good for agriculture, but they're
a challenge for managing water and nutrients.
So, all of this comes together, at least in my mind to make Florida a, an excellent
place to study and determine best management practices.
That may, in fact, even be applicable to other places in this country and also
around the world. So, I think Florida is and will be leading
the way in determining best management practices for agriculture and adopting
sustainable agriculture land management practices.
I hope you'll agree.
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