古老的格言，“我们永远不会超过三个星期的距离干旱，”在南部大平原的生产商常用。然而，根据财产的管理，干旱可能比某些思想更近，而且对他人的相当多。即使牧场和土壤相似，3英寸的雨可能导致不同生产者的不同结果。可观察的方差往往是“有效”降雨的差异的结果。
Effective vs. Total Rainfall
有效的降雨是在降雨事件后渗透到土壤中的水分。降雨量是落在财产上;有效的降雨是进入土壤的东西。
太多的是，从良好的降雨事件中的大部分雨中最终逃离了它落后的区域，并从房产和下游旅行。降雨量越多，饲料越大，饲料的潜力和随后的牲畜生产越大，牧场的弹性越大，承受短期和长期干旱条件。
Build Organic Matter to Capture More Water
那么影响我们的土壤和牧场可能是如何影响的因素是什么？
Much of the variance observed in effective rainfall and the lack of drought resiliency of pastures can be attributed to a lack of water-holding capacity. Water holding capacity is influenced by soil type, previous management and organic matter in the soil.
There is little you can do about the soil types of your property. Inherently, some soil types hold more water than others. For example, good loam and clay loam soils hold more water than a sandy soil. However, you do have influence on other variables that directly affect the amount of organic matter that accumulates in and on the soil.
There is a correlation between soil organic matter and water-holding capacity. The greater the amount of organic matter in and on the soil, the greater the water-holding capacity and the more drought-resilient soils and pastures will be regardless of the soil type.
No. 1 Recommendation: Keep Soil Covered
在这五项原则中，保持土壤覆盖的通常是开始增加土壤有机物的最重要原则。
保持封面不仅重要，重要的是要考虑封面的类型。活植物和植物垃圾都是封面的重要组成部分。在一个理想的情况下：
There is never bare ground in the pastures and the plant material growing in and on the soils are healthy, productive and managed so that there is plenty of plant material remaining during the growing and dormant seasons.
Adequate residues are maintained following grazing events and across all season allowing for some plant litter to mature, deteriorate with age and accumulate at the soil surface.
利用生产性草，根系系统是强大的，具有适当的营业额和再生，并与饲料生产同时发生。
为了增加有效降雨量，生产者需要以与土壤健康原则互补的方式管理牧场。
Grazing livestock are managed so that plants are never/rarely grazed severely and receive adequate recovery before being re-grazed.
With this description of proper management to enhance organic matter in and on the soils, a producer incorporates other soil health principles too: soil disturbance is optimized, grazing livestock are incorporated and a growing root is in the soil at all times. In many instances, it means plant diversity contributes as well. To increase the amount of effective rainfall, a producer needs to manage their pastures in such a manner that is complementary to the soil health principles.
径流与多英寸下雨很常见
考虑一下，俄克拉荷马州中南部的平均降雨量每年约为35-36英寸。降雨事件的变化范围从痕量量到超过5英寸的偶尔事件。
在一个有利的一年中，该地区在不断增长的季节体验多于3英寸的雨季事件并不罕见。在这样的岁月里，发生了重要的径流。这填满了池塘和湖泊 - 一个有价值的好处 - 但是一旦池塘填充，剩下的水分就会丢失。
So how much rain falls on our pastures before it begins to run off? How much of the total rainfall is effective? Unfortunately for many producers, most pastures incur runoff with multi-inch rainfall events.
让我们来看看一个轶事的例子：
年降雨量为36英寸的生产商常规观察径流，下雨大于1.5英寸。看着俄克拉荷马州Mesonet的每月降雨报告过去几年，我们观察到该地区的年降雨量的三分之二来自1.5英寸的活动。随后，大约12英寸（36英寸36英寸）的雨发生在小于1.5英寸，24英寸（三分之二英寸36英寸）的雨中来自较大的雨水事件（超过1.5英寸）。
平均而言，我们每年看到大约八个大雨。假设任何超过1.5英寸的降雨将径流，这八个活动的有效降雨量为12英寸（8个雨事件×1.5英寸）。这款生产国36英寸总降雨量的总有效降雨量约为24英寸（距离雨季12英寸，距离距离超过1.5英寸，12英寸超过1.5英寸）。这个例子不是那么不寻常。
如何获得20,000加仑的水
Most soil samples that come through 188bet金宝搏代理Noble Research Institute’s soil testing facility are near or below 1% organic matter. Therefore, it is easy to conclude that only about 24 inches of our annual rainfall is effective for some if not many 1% organic matter soils in south-central Oklahoma.
一般来说，有机物增加1％的增加对应于土壤水持量的增加约20,000加仑的每英亩或大约十分之一的雨水。通过将土壤有机物质增加到2％至2％，将在土壤中浸润更多，发生较少的径流。
When applied to our previous example, the point of runoff increases from 1.5 inches of rain to 2.2 inches of rain. Only about 40% of rain events are in excess of 2.2 inches, and there are generally about five of those annually. Effective rainfall increases to 21.6 inches (36-inch annual rainfall × 60%) plus 11 inches (2.2 inches x 5 events) equals 33.6 inches.
土壤有机物增加1％的含量有效降雨量有显着差异。在这个例子中，它增加了40％。插入饲料生产的相应增加并不困难。实际上，由于在休眠季节发生了一些雨水，这并不总是这样做。但是，如果有效降雨量增加40％，则生产和承载能力增加20-30％，这仍然是有益的。也许更重要的是长期，它会在土壤和牧场中产生更大的弹性，使得两者易受干旱的影响。
Imagine what an additional percent increase or two would do!
