FALL SEMESTER - October 21

October 21

Today we talked about N and P in agriculture. 

Fertilizer run-off in agricultural systems can compromise water quality at the regional level. The detrimental effects on the ecosystems are cost effective and difficult to manage. According to a new study in Science, there are now 405 identified dead zones worldwide as the direct result of fertilizer runoff and fossil-fuel use lead to massive areas in the ocean with scant or no oxygen, killing large swaths of sea life and causing hundreds of millions of dollars in damage

This is no small economic matter. As it stands, roughly 83,000 tons (75,000 metric tons) of fish and other ocean life are lost to the Chesapeake Bay dead zone each year

More than 212,000 metric tons [235,000 tons] of food is lost to hypoxia in the Gulf of Mexico

The primary culprit in marine environments is nitrogen and, nowadays, the biggest contributor of nitrogen to marine systems is agriculture.

So much nitrogen is now reaching these coastal waters that much of it ends up buried in sediment, even when new nitrogen sources are removed through sound agricultural practices, those sediments release that nitrogen over time, perpetuating the cycle.

Many studies had looked into integrated management systems to mitigate the effects. 

Effect of Surface Incorporation of Broiler Litter Applied to

No-Till Cotton on Runoff Quality

Adeli et al. 2011

Since surface application of broiler litter to no-till cotton could lead to degradation of water quality…

A 2-yr field study was conducted on a silt loam upland soil to determine the effect of incorporation of broiler litter into the soil surface on nutrient and bacterial transport in runoff.

The experimental design was a randomized complete block with four treatments and three replications: (i) unfertilized control; (ii) surface-applied broiler litter without incorporation; (iii) surface-applied broiler litter with immediate incorporation; and (iv) inorganic fertilizer N and inorganic fertilizer P.

Runoff was collected from small runoff plots (2.4 m by 1.6 m) established at the bottom side of main plots (13.7 m by 6.0 m).

Incorporation of broiler litter reduced total N, NO3-N, water soluble P, and total P concentrations in runoff by 35, 25, 61, and 64%, respectively, and litter-associated bacteria by two to three orders of magnitude compared with unincorporated treatment.

FALL SEMESTER - October 14

October 14

Thinking about today's class on Manures and the Nitrogen Cycle, i made the connection to an interesting paper I read a few year ago by Eagle et al. Here's an extract of theta hundred and so paper.

N₂O mitigation potential of agricultural land management through irrigation (Eagle et al. 2008)

The use of irrigation in agricultural fields is known to increases the potential of N₂O emissions by means of reducing aeration in the soil and increasing microbial activity. Studies comparing irrigated versus non-irrigated fields show an increased N₂O flux of 0.05 t CO₂e ha-1 yr-1 on irrigated versus non-irrigated turf grass (Bremer 2006), and an average difference of approximately 0.7 t CO2 e ha-1  yr-1  between 28 dry land and 13 irrigated land experiments (Liebig et al. 2005).

There is a significant number of “best management irrigation practices” available to mitigate N₂O emissions in agricultural fields. Studies show that by reducing the total amount of water applied and optimizing water distribution to root zones, irrigation efficiency gains can provide water savings as well as GHG benefits. Total N₂O emissions after a reduction in irrigation intensity have been measured to decrease by between 0.1 t CO2e ha-1 yr-1 and 0.9 t CO2 e ha-1 yr-1 (Rochette et al. 2008, Scheer et al. 2008, both studies taken from in Eagle et al. 2012). Scheer et al. (2008) determined that reducing irrigation intensity (irrigating cotton when soil moisture was at 65% instead of 75% of field capacity) reduced N2 O emissions by almost 50% (0.94 t CO2 e ha-1 yr-1), and similar effects were observed on winter wheat fi elds, although the total impact was lower because of lower baseline emissions (Eagle et al. 2012).

Studies by Kallenbach et al. (2010) and Amos et al. (2005) also documented significantly lower N₂O fluxes with drip and buried tape (versus surface) irrigation, although annual mitigation effects could not be determined because of relatively short-term flux measurements (Eagle et al. 2012).

Taken from: 

Eagle, A., L. Olander, L.R. Henry, K. Haugen-Kozyra, N. Millar, and G.P. Robertson. 2012. Greenhouse Gas

Mitigation Potential of Agricultural Land Management in the United States: A Synthesis of the Literature. Report NI

R 10-04, Third Edition. Durham, NC: Nicholas Institute for Environmental Policy Solutions, Duke University

FALL SEMESTER - October 7

October 7

Today, we looked into Bed Shapers and Seeders. Some of the parts of these tools were new to us, so I thought it would be a good idea to put a picture to the name. Specially for City Folks such as myself...

Seeder Parts 101!

Over time, seeders have been designed to manage residues on the soil surface and at the same time to place the seeds. 

Today, direct seeders have following working elements:

• A disc to cut through the surface mulch and open a slot in the soil

• A furrow opener to place the seed - either a chisel or a double disc

• Wheels to control the planting depth and eventually press the seed row

• Press wheels to close the slot in order to secure a good contact between soil and seed

FALL TERM - Sep 30

September 30

Today we talk about primary and secondary cultivators, and although we were familiar with the words till, no-till, and ploughing, we learnt that there are several types of tillage:

Tnau Agri Portal. Types of Tillage http://agritech.tnau.ac.in/agriculture/agri_tillage_typesoftillage.html

Tillage is also defined by the type of activity (From FAO: Conservation Agriculture. Machinery, Tools and Equipment):

• Inversion: this type of tillage turns over the soil in the part that is worked. Surface layers are completely incorporated and deeper soil layers are brought to the surface. The argument that ploughing controls weeds is not valid when done every year, as the same amount of weed seeds is brought to the surface.
• Mixture: this operation mixes all materials more or less homogeneously to a certain soil depth, which is usually around 10 cm.
• Ripping: this type of tillage breaks the soil open, in order to loosen the soil without moving the clods, for instance in soil de-compaction operations (subsoiling).
• Pulverize: this operation crumbles the soil clods in order to form a very fine horizon, i.e. the seedbed. It is executed within a few centimetres from the surface.

At least four types of tillage operations can be distinguished in a conventional system (From FAO: Conservation Agriculture. Machinery, Tools and Equipment):

• Clearing the land and management of residues, including burning fallow vegetation or residues.
• Primary tillage.
• Secondary tillage.
• Crop management activities, like weeding, ridging, breaking crusts, etc.

FALL TERM - Sep 23

September 23

Harvest time at the orchard

We finished our harvest at the orchard. 
Time Tool Presentation: Fertilizer Spreaders

There are a few diseases that cause the top of carrots to turn yellow. The problem with this foliar disease is that it causes the top to snap off when you are trying to pull them. A lot of mechanical harvesters work by ripping and pulling, and this can be a problem when these diseases are present.

The weeds are taking over the fields, however, at this stage, they are not detrimental to the crops. Weeding easily in the season when crops like corn were establishing did pay off.

In spite of a great harvest, the apple trees are going to go. They will be removed. They had suffered considerable root rot over the years. There's also the intention of removing them to put some tile drainage for the annual crop production.

FALL TERM - Sep 16

September 16

Harvest at the Orchard

The Story of the Corn Maidens*

According to tradition, Corn Maidens were created in the palm of the right hand of the Great Spirit as guides for the people of the Earth. People were not always able to determine from among the many plants and animals on the Earth what was good for them to eat—what would nourish them vs. what would harm them. So the Corn Maidens were sent to give each clan a single seed of corn that, if properly cared for, would feed and sustain them.

The people took their seeds of corn and planted them in the ground, making a small mound around them. The Corn Maidens sang a song that inspired love and faith in the people. Some people began to tend to the small mound, offering water and caressing the soil around the seed.

Slowly, the corn grew, breaking through the Earth. Like a child, the plant grew strong and beautiful with the love and prayers provided by the people. As the plant grew, the people began to realize how cared for they were by the Great Spirit, and their faith grew, too. As their faith grew, mature ears of corn sprouted from the plant. With the people having the food they needed, the Corn Maidens were no longer needed, and so they returned to their spirit form.

While the Corn Maidens were among the people, some men wanted to make them their own because of their great beauty. To protect themselves, the Great Spirit told the Corn Maidens to place one of the sacred images of the kachina on their heads. Disguised as the kachina, the men could no longer recognize one Corn Maiden from another, making them unable to pursue the Corn Maidens

Story taken from “Corn Maidens” as told by Andy P. Abeita © 1998 Laborex Enterprises

The Orchard

Just as we did at the Terraces, we are starting to get the fields ready for planting our cover crop for the winter. We harvested the remaining potatoes, pumpkins, and corn. As we harvested, we observe a significant presence of thistle and large patches of night shade (a Solinaceae) in the potato fields. Some of the night shades had flowers, but we think we tilled them before they could add to the seed bank.

Dense patches of Night Shade...

and thisle

We observe the presence of wireworms in some of the potatoes...

Potatoes variety: Cascade, planted May 21

FALL TERM - Sep 9

September 9

First class of our Fall semester. By now the Lower Mainland has received enough effective precipitation to lift most of the water restrictions that were placed during the summer. Some experts believe that in spite of the rain that has fallen so far, it will take some time for the local aquifers to recover from this sever summers drought. It will be interesting to hear more detailed reports from the field on the overall performance of crop production in the region under this extreme weather events. Specially when according to experts, this is going to become more the norm that the exception in our area.

Metro Vancouver water supply declining at ‘startling’ rate

 Low rainfall in May and June, current heat wave get the blame

BY DAN FUMANO, THE PROVINCE JULY 8, 2015

http://www.theprovince.com/Metro+Vancouver+water+supply+declining+startling+rate/11190123/story.html

HARVEST TIME AT THE TERRACES!!

Season of the Harvest - by Joseph John Taras Kushnir

Shrouded in leaves of orange 
and vibrant yellow is the
bountiful yield of the giving harvest.
The fruition of carefully 
planted plans unveil itself
in shades of succulence

GREEK MYTHOLOGY - DEMETER AND PERSEPHONE

The Reason for Seasons

Ancient Myths & Folktales for Kids

Retold by Lin Donn

Zeus, the king of all the gods, had two brothers and three sisters. Each had an important job. His sister, Demeter, was in charge of the harvest. If Demeter did not do her job, the crops could die, and everyone would starve. It was important to keep Demeter happy. 

Demeter loved her little daughter, Persephone. As Persephone smiled up at her mother, Demeter's heart swelled with happiness, and the crops grew high and healthy. 

Hades, the king of the underworld, was a gloomy fellow. One day Hades fell deeply in love with Persephone. Before anyone could stop him, he grabbed Persephone, and dove deep into the darkest depths of the Underworld.

Hades locked Persephone in a beautifully decorated room in the Hall of Hades. He brought her all kinds of delicious food. Persephone refused to eat. She had heard if you ate anything in Hades, you could never leave. 

Over a week went by. Finally, in desperate hunger, Persephone ate six pomegranate seeds. She promptly burst into tears.

She was not the only one crying. Demeter, her mother, missed her daughter terribly. She did not care if the crops died. She did not care about anything except finding her daughter. No one knows who told Zeus about it, but it was clear this could not go on. Zeus sent his son Hermes to work a deal with Hades.

This was the deal Hermes worked out: If Persephone would marry Hades, she would live as queen of the Underworld for six months each winter. In the spring, Persephone would return to earth and live there for six months. 

Every spring, Demeter makes sure flowers are blooming and crops are growing and the fields are green with welcome. Every fall, when Persephone returns to the underworld, Demeter ignores the crops and flowers and lets them die. Each spring, Demeter brings everything to life again, ready to welcome her daughter's return.

To the ancient Greeks, that was the reason for seasons - winter, spring, summer, fall.

Slowly, we are starting to prepare the beds for the fall-winter cover crop, by harvesting the remaining crops and pulling out the plants.

The Cucurbits made a good come back after the powdery mildew, and the leaves look rather healthy...