21

The way hillsides are farmed generally depends on the steepness of the hillside. Gentle slopes can be farmed the same way flat land is farmed. Steeper slops require the hillside to be divided into terraces. The steeper the slope, the narrower the terraces. Terracing of hillsides in farming reduces erosion because terraces reduce the flow rate of water down ...


13

Terrace farming is widespread in the Orient but it is backbreakingly labour intensive. In UK we don't do it, partly because we don't grow our own rice. Depending on how steep the hill is, we either plough it or use it for grazing. A shallow incline can be ploughed, but you have to be very careful how you do it. Many accidents are caused each year by ...


7

Raising herd animals would likely contribute more than mere farms. Many farms simply produce feed for animals anyway, and this can lead to an inflated population which can wreck havoc when released in the wild to graze. That said, with the exception of Egypt and a few rare cases, every agricultural society eventually failed because they could either could ...


7

Acid/Base Chemistry Gaseous ammonia (NH$_3$) acts as a base when it dissolves in water. The reactions are below. NH$_3$(g) + H$_2$O(l) $\rightleftharpoons$ NH$_3$(aq) NH$_3$(aq) + H$_3$O$^+$(aq) $\rightleftharpoons$ NH$_4^+$(aq) + H$_2$O(l) The end product is an ammonium ion. We also have gas phase species SO$_2$ and NO$_2$ in air. They dissolve in water ...


7

Some people use swales on hillsides for farming. Swales are basically a trench that runs along contour lines of a slope and is used to slow water runoff and increase infiltration into the ground. They're good for growing things like fruit trees, berry bushes and grape vines. Once one is created it usually doesn't take a ton of work to maintain.


7

It entirely depends on what crops you're farming. Note for example how many vineyards (especially European ones, from my observation) are located on steep hillsides. In other places, such as the US northeast, you might farm dairy cattle on the hills, or grow maple trees. IOW, conventional farming of annual crops on hillsides is labor-intensive (and the ...


5

I could find a relatively recent review by Mills et al. (2007) that lists sensitivity to ozone for several crops. Among the most sensitive were (table 1) Watermelons (albeit with very few data points used) Pulses Cotton Wheat While the most resistant crops were Barley Fruits (Plums and Strawberries) Broccoli The measure for ozone used in this review is ...


4

Soil is not a single uniform material. When wind erosion takes hold, as in the infamous 'dust bowl' of the 1930s, it is the uppermost A horizon, and to a lesser extent the B horizon that is mainly lost. The lost soil takes with it most of the organic carbon, and it is this component that is most difficult to replace. Rates of soil loss are primarily ...


4

I don't know much about Scandinavia in the 1500's, and in particular, how much was forested. However, one can say that the whole area was previously glaciated, with much of the topsoil being eroded away by ice, so soils generally tend to be thin, immature, sandy and nutrient poor. We do know that conifers predominated, leaving a soil-litter of pine needles. ...


4

The area outlined covers several climatic zones. The northeastern part was, and to some extent still is, permafrost at shallow depth, so obviously this was not good for agriculture. Further south most of the area outlined is covered in podzols, which are generally sandy and nutrient poor. Therefore, where water availability is not a limiting constraint (and ...


4

Tropospheric ozone is a significant greenhouse gas (see e.g. IPCC AR4) and has well established negative effects on crop yields. For example, Van Dingen et al (2009) evaluated yield losses of up to about 15% globally, depending on the crop.


4

First look at the article, is cites no sources and is not written by an an expert. It is written without peer review and does not seem to understand how to measure nutritional content (brix is only a measure of sugar not minerals) or what controlled conditions are. No methodology for collection, type of hydroponics, sample size, or anything else is given, ...


4

One issue that you've got is the area will be contaminated with fragments of plastic that are microscopic in size to large pieces and they will be at varying depths throughout the soil. To most people that wouldn't be much of a problem, but for you, who wants to grow food with an organic certification it's going to be a major problem. Setting fire to that ...


4

There are a number of factors that went/are going into the population explosion, food is only one vaccination and antibiotics are a big factor as well. within food fertilizer is again only one of many factors. Better crop strains, mechanized and better farming techniques, soil science, pesticides, refrigeration, and a dozen other factors contributed. Keep ...


4

How do farmers plow on uneven terrain? Simple answer - they don't. if traditional farming techniques are used. Traditional for who? In rice farming areas, the tradition is terraces and paddies. No ploughing needed, and planting was entirely human-powered. In Europe, the tradition is animal herding. Areas with upland pastures lend themselves to cattle ...


3

Disclaimer: this is probably TLWR, but you can absolutely apply some physical reasoning to arrive at the answer. Changes in surface height of the earth are governed by the conservation of mass, i.e. that if mass ($M$) is removed in one location (everglades soil erosion), then an equal amount of mass must be gained at another location (perhaps accretion on ...


3

You probably mean 50kgN/ha, which sounds like a plausible number for fertilizer application. I don't know what you are doing exactly, but you need to know how much surface area your soil sample represents. If you do planting tests, it will be simply the surface of your bed. Then it's just mulitplying the surface area by 50kgN/ha (mind the units!). Now you ...


3

Quantitatively hydrogen fluoride is insignificant, except when it is emitted from volcanic sources, in which case it is extremely toxic to crops - far more than any other natural gas. Possibly the worst recorded case was from Iceland when the volcanic eruption of 1783-1794 killed most if not all the crops and livestock downwind. The combination of fluorine ...


3

The ecological footprint is the impact of a person or community on the environment, expressed as the amount of land required to sustain their use of natural resources. A global hectare (gha) from Wikipedia: One global hectare represents the average productivity of all biologically productive areas (measured in hectares) on earth in a given year. and... ...


2

EDIT -- Found the full report ... in Norway. The quote you are trying to source was an oft repeated (1999-2002) talking point by Klaus Toepfer (Töpfer), head of UNEP. The oldest instance I can find is in London, 1999. The rate at which arable land is being lost is increasing and is currently 30-35 times the historical rate. Only about one and a half ...


2

It's a curious question. I agree with Gordon Stranger, without context, (and a mention of some link to peer reviewed research, or at least, some kind of measurement), it's pretty meaningless. I did a a google search and checked links with books.google.com in them to search for a source but everything refers back to UNCCD and UNCCD, as far as I read ...


2

No context is given, but at face value this is a meaningless quotation. Globally there is a net increase in arable land from close to zero about 8000 years ago, to the current maximum of just over 40% of the gross biological productivity of the planet. 'Arable land loss' can refer to the land lost to urbanization, salinization or desertification. One might ...


2

To add to Trevor's answer, FACE experiments have shown that elevated CO2 can affect grain quality and the food product. For example bread made with wheat flour grown under elevated CO2 doesn't rise as much as flour from identical varieties grown under current conditions.


2

Specifically looking at carbon dioxide, there's been a series of field experiments that involve artificially raising the local CO2 levels for different plant species and seeing how they reallocate this carbon and develop. Results from the Free Air Concentration Experiments (FACE) have been published for the past 25 years and can be found in some pretty major ...


2

The agricultural regions of Canada: are located on suitable soil types: Much of the unfarmed area is the Canadian Shield (shades of red below): The current surface expression of the Shield is one of very thin soil lying on top of the bedrock, with many bare outcrops. This arrangement was caused by severe glaciation during the ice age, which covered ...


2

There are several aspects to be considered in this apparent difference. First, your quote from Wikipedia describes the change in productivity but does not account for other factors that have lead to productivity increase such as changed farming practices (larger, more sophisticated farm equipment, improved use of weather and soil data, etc.) changes to crop ...


2

It looks like cannabis. Mature cannabis plants are are tall & "skinny", like the ones in the picture. Also, the density of plants, per unit area of land, suggests it's a plantation crop, quite possibly for illicit purposes.


2

As our planet gets warmer less area will be avaliable for farming so vertical farming will be needed to supply food for a growing population. Vertical farming will not replace traditional farming but it will be an addition to this. Vertical farming can be effective in growing food by using less energy,We can use only the part of the light spectrum that ...


2

There are several contributing factors, livestock, Livestock is easy animals produce co2 but their methane is a bigger problem, methane is a better greenhouse gas than the co2 that the feed plants took in. Livestock waste is also a problem , people do not realize how much waste modern factory farms produce, specially when stored as a liquid is it ...


2

Organic matter affects the pH and makes the soil more acidic. The best example of this is in peat bogs, where only acid tolerant plants can live and the peat is so acidic that micro-organisms don't flourish, thus preventing decay. There is the famous Tollund Man, found in a peat bog in Denmark if I remember rightly. The body is in an almost perfect state of ...


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