This page is an automatic translation to Chinese of Terraces and ditches at Petegral.This translation is distributed in the hope that it will be useful, but without any guarantee of accuracy.Read more...

墨西哥瓦哈卡州佩特雷加尔永续农业示范中心的露台和沟渠。

梯田和沟渠可以防止陡坡上的侵蚀，并创造农田。梯田和沟渠是根据场地的轮廓挖掘的，梯田在每个沟渠上都留下了边缘。水不是沿着这些梯田的边缘直接流下山，因此这种做法可以减缓水流速度并防止大规模的土壤侵蚀。如果将香根草（一种高大的多年生草）种植在土丘中，它有助于进一步防止侵蚀，因为它的根深深扎入土壤中以将其固定到位。这些沟槽之间的距离取决于坡度。Petegral 展示了植被梯田以及使用岩墙边界的梯田。这是该县一系列水土保持、地下水回灌、农业示范工程中的一个项目。位于墨西哥圣安德烈斯瓦亚帕姆的永续农业示范中心，名为佩德雷加尔。

森林砍伐是造成土壤侵蚀的最大原因之一。如果没有树根牢固地形成基质来稳定土壤，土地就会受到斜坡和山丘的侵蚀。剩下的土壤就任由风雨的摆布，这些侵蚀的土壤将它遇到的一切都拖了下来。^[1]在瓦哈卡州以及墨西哥的其他地方，农民（或小农）被赶出了他们的土地，并且经常发现他们的小农场唯一可用的土地是森林覆盖的山坡上。因此，Petegral 希望建立一个中心，展示在以前森林砍伐的陡坡山上农业的不同应用。他们展示的一些技术包括：梯田、沟渠、多年生草的缓冲区以及混合或混养种植。

露台

梯田有助于减少土壤侵蚀。梯田沿着平坦的地面围绕倾斜的景观弯曲。梯田彼此平行，沿着山势水平分布，从而创造了一条新的水流路径，有助于减缓水流的流速。减缓水流速度可以：水可以更长时间地渗透到土壤中，供植物使用和当地含水层的再生，并且可以减少在山洪暴发的高雨期发生的侵蚀。瓦哈卡州的年平均降雨量为 1051 毫米（或 41.38 英寸），但其中大部分发生在 6 月，12 天内的降雨量约为 263 毫米（或 10.4 英寸）。这意味着下雨时会下很大的雨，侵蚀是整个瓦哈卡州反复出现的问题。^[2]

露台和楼层的建造

要建造露台，您必须找到平坦的地面。在水平地面上，您需要标记露台的边缘，只要山的轮廓允许，就可以继续这样做。用于寻找水平地面的设备包括下面便宜且功能齐全的设备 A。

设备A架

材料

1. 2根2.5米长的木棍
2. 坚固的金属丝将木棍固定到位
3. 1根2米长的木棍
4. 3米抗拉丝悬挂
5. 大约 1.5 公斤重的岩石或其他物体，以在悬挂的电线上产生张力

建造设备A

• 3 根棍子应形成 A 形，每条腿固定在距中心相同的距离处，距中心约 30 厘米。
• 中心水平杆应放置在侧腿上方 2.10 m 处，在腿成角度后，其最终位置略高于臀部高度。
• 岩石应悬挂在距中心水平棒顶部 5 厘米处
• 最后标记中心水平杆上的中点，如果地面水平，岩石应该悬在此处。

使用设备 A 寻找水平地面

• 确定第一个露台的高度并用木桩标记该点。
• 在桩点处倾斜装置 A 的一条腿，在定位第二个点时应保持固定。
• 移动第二条腿，直到中间的悬挂线越过中央水平杆上的中央标记。这就是水平。
• 然后在第二点钉上一根木桩。
• 对总轮廓继续此过程。^[3]

梯田植被系列植物

方案 1：玉米行和草沟缓冲区

玉米行和草沟缓冲区系列植物

喜水草、灌木、树木

• Starting from the river edge a series of first water loving grasses, then shrubs, then small trees are established going out from the banks. This natural pattern was repeated at Petegral after microfilter dams were placed along the creeks and river to help remove soils and silts from flowing off the land and into the water way and to create zones of revegetation along these creek beds. This series of grass, shrub, small tree goes out from the bank for 20 feet. The roots of the vegetation forms a matrix that helps secure the soil in place.

Walkway with Pine Tree Border

• After this series Petegral has a narrox walk way for maintenance, that is as wide as a wheel barrow.
• After this walkway baby pine trees have been planted and annual grasses grow up hill for another 6 feet.

Corn Milpa in Rows

• After the second series of grasses a corn ¨milpa¨ is planted containing 9 to 10 rows of corn over 20 feet of run up hill, with corn planted for as long horizontally as the contour of the terrace will allow. The corn is planted on raised beds that are less then 6 inches high and squash plants are intersperced between corn plants. While corn grows tall, these squash grow wide providing further ground cover for freshly tilled soil.

Buffer of: Grass, Vetiver, Ditch, then more Grass

• After the milpa perrenial grasses grow for 5 to 6 feet of run. On the furthest edge of these grasses, vetiver, a very hardy grass is planted. Vetiver has a crystaline structure in its cells, which makes it very sharp and unapatizing to many animals and especially popular for soil restoration efforts.
• Ditches are generally 2 ft wide and the depth depends on the slope, amount of rainfall, and vegetation. Vetiver grass can be planted on the edge of a ditch that is 5-12 inches in height, while on the higher edge maguey cactus can be planted on the edge of a ditch that varies from 12- 17 inches in height.

More Corn and more Buffers

• After the buffer series another corn milpa of 9-10 rows of corn follows, with this sequence repeating itself all the way up the hill. In total the eastern facing hill has 4 of these milpas.

Option 2 with Polyculture Corn mix, No Till, and Ditches

Polyculture and No Till Techniques

• Rather then planting in rows and tilling, the west facing slopes instead use a dig technique where only about one foot in diameter of the soil is directly disturbed for planting corn or beans. This reduces the disturbance of the soil and allows for the natural soil cover and vegetation to remain.
• A polyculture of many different plants are intersperced among one another including: corn, beans, squash, cactus, shrubs, and wild grass. Tall annual grasses also establish themselves in between the plants much easier with this technique and may cause some problems with shading.

Series of Plants with Polyculture, No till, and Ditches

Grass, Shrub, Trees from river edge

• from the river bottom there is about 30 ft of wild grasses, established shrubs, trees, and fruit trees.

Polyculture with Corn

• then about 20ft of polyculture mixed corn, beans, cactus, shrubs, and fruit trees.

Ditch

• then a ditch that is 1.5 ft wide and vetiver planted on the lower side of the ditch

More Polyculture and More Ditches

• the polyculture mix is repeated and then again followed by another ditch all the way up the hill

Planting Vetiver

Timing to Plant Vetiver

Planting vetiver is best done at the same time corn planting is done. The rainy season should be well established by this time, around May and June, depending on the location, this rain will allow for there to be sufficient soil moisture for the vetiver. If irrigation is available all year, then its best done when the danger of frost is gone.

Taking Baby Plants from an Older and Full Bed

Even though an adult vetiver plant is very strong and resilient, newly planted plants are delicate and should be treated well so that the seed will not fail. Newly uprooted baby vetiver plants taken from the edges of older beds, should be placed in a nursery with high humidity. Prune back baby grass leaves till the blades are only 20cm tall, this is partly because the disturbed and reduced root structure, after being dug out of the edge of the bed, can not support the same amount of foliage. Also prune back the roots to 10cm, partly for increased ease in replanting the baby vetiver. Each plant must have 2 or 3 healthy looking stems.

How to Plant Vetiver Barriers

In a place where rain is scarce vetiver should be planted at the bottom of the ditch, in a place where it rains a lot is better to be planted at the edge of the ditch. Planting can be facilitated with a simple planting stick or shovel. Baby plants should be planted along the contour with about 10cm between each plant. The field should be well wet, and the baby plant should be planted about 3 cm below the surface of the earth and the soil slightly compacted on the sides.

A barrier is fully established when the plants have come together and form a dense row.

References