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FALL WOODY PLANT CONTROL – Megan Taylor
As we transition into fall are you seeing more brush and woody weeds in your pastures?
It can be tempting to spray herbicides in fall to manage woody plants and brush. I have been receiving several calls over the past two weeks about spraying woody plants in conjunction with thistles. However, counter to what is recommended for thistles, fall spraying may not pay for woody weeds. Spraying can still be completed on deciduous woody plants if the leaves are still green and actively growing, for many in Nebraska this has already passed and we don’t want to make applications on dormant plants. Mowing for brush or smaller woody plants can be completed in fall, but will need to be chemically controlled in the following summer to reduce populations. So, fall may serve as a time for collecting information, making a plan for late spring to early summer, and questioning why woody plants have encroached.
Right now make a plan for June!
- Know your weeds you are controlling and pick products
- Make a plan for grazing restrictions after treatment
- Adjust management practices to increase competition in favor of desirable grasses
Typically, early June is the best time to control woody plants and spraying early rather than later is recommended. So, if we have a warm spring and break dormancy early, spray accordingly. Also, overgrazing and fertility play a big role in encroaching woody plants, so looking at past records and soil sampling may be a better use of time this fall, than actively spraying.
Bottom line: spraying now won’t pay for woody weeds, wait until early summer and use this time to plan ahead/adjust grazing schedule.
VALUING CORN STALK BALES – Ben Beckman
With dry conditions still plaguing much of the state, baling corn residue following harvest might be an optional roughage source if hay supply is getting tight. What value should be put on harvesting corn residue?
Figuring out the true value of corn stalk bales can be a bit tricky, but breaking down the costs can help it make sense. First, look at the value of nutrients removed from the field that will need to be replaced by fertilizer. Stalks this fall will contain between $3-5 worth of nitrogen, potassium, phosphorus, and sulfur per ton.
Stalks also provide organic matter and help reduce erosion. We need to account for the loss of these benefits as well. Nebraska research shows that dryland corn yield declines about 2 bushes for each ton of residue removed. Irrigation costs increase similarly to maintain yields, accounting for an additional $10-12 per ton.
Baling stalks is harder on equipment than putting up grass or alfalfa hay. This additional labor and equipment cost comes in at around $20-25 per ton. Adding everything up, we accumulate $33 to $45 in cost per ton of residue removed.
With costs calculated, we have to figure out what a bale is worth. From a nutritional standpoint, corn stalk bales don’t come out much better than straw. Even if being selective with what we harvest, we can only count on around 5% crude protein and up to 55% TDN. With these values, combining stalks with distillers grain in a diet may be the most efficient use. Comparing a distillers grain and stalk ration with a mixed grass hay diet, we can put a value on corn stalk bales up to $80 per ton.
So, is corn stalk harvest worth it? This year with fertilizer prices down, and hay up, corn stalk bales may be a reasonable option to explore.
ALFLAFA IRRIGATION IN THE FALL – Megan Taylor
With warm and dry conditions across the state should we be irrigating alfalfa one more time?
With the continued lack of moisture that we have across the state of Nebraska and the warm autumn temperatures, alfalfa stands may benefit from added water. Alfalfa is a drought tolerant crop with a deep root system, however it does have a relatively high water use requirement. This means that alfalfa can survive between long breaks of irrigation or rainfall events due to its deep root system. However, timely application of water and recharge are critical for success of the stand over time. We need some surface soil moisture to prevent alfalfa roots from drying out and dying over winter, but too much surface moisture, especially in new stands, can stunt the root development of alfalfa. Soil moisture can help to regulate soil temperatures from dropping too low for alfalfa plants to survive and application of water now in heavy textured soils could allow water to move through the profile for spring capture.
During the peak water use period in summer, it is unrealistic attempt to keep up with the water demand of alfalfa with irrigation alone. Relying on water reserves available in the deeper portion of the root and soil profile are valuable to production. Irrigating in October and into November until soils freeze thus can protect plant roots and improve yields by mitigating stress on alfalfa stands). There are two main advantages to late season water application.
- Low evaporation compared to summer, permitting very high irrigation efficiency.
- Moving water lower into the profile for spring.
Most irrigated fields of alfalfa never get much water below 4 feet deep, but alfalfa’s powerful taproot can extend 8 feet deep. Allowing for extended water capture capabilities and application of water in fall can help to build a reserve lower in the profile. That water reserve will help to mitigate stress next year while alfalfa is growing rapidly during next summer’s heat and allow you to irrigate on a timelier basis. Since many alfalfa soils have low water infiltration rates, irrigating now may provide an advantage to next spring and summer. It is important to note that irrigating in fall will not be silver bullet to recharging dry profiles, but should be used as a way to mitigate stress on alfalfa stands following dry conditions.
