Tag Archives: Crop rotation

Crop Rotation has Effect on Soil Bacteria

Crop Rotation has Effect on Soil Bacteria

Crop rotation is a well known way to improve soils. This article discusses the relationship between crop rotation and soil bacteria. In summary, soils that are rotated have a more diverse, heather population of soil bacteria.

The complete article on soil bacteria is below.

 

Crop Rotation has Effect on Soil Bacteria

Crop rotation has been used since Roman times to improve plant nutrition and to control the spread of disease. A new study to be published in Nature’s The ISME Journal reveals the profound effect it has on enriching soil with bacteria, fungi and protozoa.

“Changing the crop species massively changes the content of microbes in the soil, which in turn helps the plant to acquire nutrients, regulate growth and protect itself against pests and diseases, boosting yield,” says Prof. Philip Poole from the John Innes Centre.

Soil was collected from a field near Norwich and planted with wheat, oats and peas. After growing wheat, it remained largely unchanged and the microbes in it were mostly bacteria. However, growing oat and pea in the same sample caused a huge shift towards protozoa and nematode worms. Soil grown with peas was highly enriched for fungi.

“The soil around the roots was similar before and after growing wheat, but peas and oats re-set of the diversity of microbes,” says Poole.

All organisms on our planet can be divided between prokaryotes (which include bacteria) and eukaryotes (which include humans, plants and animals as well as fungi). After only four weeks of growth, the soil surrounding wheat contained about three percent eukaryotes. This went up to 12-15 percent for oat and pea. The change of balance is likely to be even more marked in the field where crops are grown for months rather than weeks.

Analysis has previously relied on amplifying DNA samples. This limits scientists to analyzing one taxonomic group at a time such as bacteria. It also means that everything present in that group is analyzed rather than what is playing an active role. Every gram of soil contains over 50,000 species of bacteria so the task is enormous.

There are relatively fewer actively expressed genes, or RNA. It is now possible to sequence RNA across kingdoms so a full snapshot can be taken of the active bacteria, fungi, protozoa and other microbes in the soil. The research was carried out in collaboration with the Univ. of East Anglia and The Genome Analysis Centre on Norwich Research Park.

“By sequencing RNA, we can look at the big picture of active microbes in the soil,” says PhD student Tom Turner from the John Innes Centre.

“This also allows us to work out what they are doing there, including how they might be helping the plants out.”

“Our work helps explain the experience of farmers in the field,” says Poole.

“The best seed needs to be combined with the best agronomic practices to get the full potential benefits.”

“While continued planting of one species in monoculture pulls the soil in one direction, rotating to a different one benefits soil health.”

Seeds can be inoculated with bacteria before planting out, just like humans taking a dose of friendly bacteria. But this does not achieve the diversity or quantity of microbes found in this study.

The scientists also grew an oat variety unable to produce normal levels of avenacin, a compound that protects roots from fungal pathogens. They expected the soil to contain higher levels of fungi as a result, but instead found it contained a greater diversity of other eukaryotes such as protozoa.

The findings of the study could be used to develop plant varieties that encourage beneficial microbes in the soil. John Innes Centre scientists are already investigating the possibility of engineering cereal crops able to associate with the nitrogen-fixing bacteria normally associated with peas.

“Small changes in plant genotype can have complex and unexpected effects on soil microbes surrounding the roots,” says Poole. “Scientists, breeders and farmers can make the most of these effects not only with what they grow but how they grow it.”

The research was made possible with funding from the Earth and Life Systems Alliance at the Univ. of East Anglia and from the core strategic grant to the John Innes Centre from the Biotechnology and Biological Sciences Research Council (BBSRC).

Specific Plant Benefits Provided by Beneficial Soil Bacteria

 Beneficial Soil Bacteria

Beneficial soil bacteria cause a number of specific plant benefits. These benefits include; larger, healthier roots, nutrient processing, and secretion of plant growth regulating substances. This post will discuss each of these plant benefits in more detail.

Beneficial Soil Bacteria Help grow Larger, Healthier Roots

There are a number of bacteria that help promote plant growth and they are sometimes beneficial soil bacteriacalled Plant Growth Promoting Rhizobacteria (PGBR). PGBR are defined as rhizospere inhabiting bacteria that have a positive effect on plant growth and plant health. There are several genera that are considered PGPR including, Bacillus, Azospirillum, and Pseudomonas.

Beneficial soil bacteria, such as Bacillus subtilis and Bacillus megaterium, produce a class of chemicals called cytokinins. These cytokinins impact roots by overproduction of root hairs and and lateral roots. This, in turn, provides the plant with an increased ability to take up water and nutrients. So, as expected, a larger healthier root system provides for a healthier plant.

Enhanced Nutrient Processing

Bacteria process a wide variety of chemicals. Often times taking in inorganic compounds and metabolizing them into organic compounds. The bacteria need phosphate for DNA and RNA synthesis and for production of ATP. The benefit to the plant of this processing is the conversion of the phosphate from an insoluble form to a soluble one. Since insoluble phosphate is inaccessible to the plant, this processing by bacteria is invaluable to the plant.

Bacteria Produce and Secrete plant Growth Regulating Compounds

Along with the cytokinins, mentioned earlier, bacteria produce a number of beneficial growth compounds  that convey a plant benefit. These include plant hormones (sometimes called phytohormones) and  auxins. Together phytohormones, cytokinins, and auxins regulate plant growth, root size, and fruit formation. Ultimately, its the beneficial bacteria that either produce these compounds or induce the plant to produce these compounds.

Custom Biologicals manufactures a wide variety of biological products for use in environmental applications. Our agricultural products include Custom B5, a blend of 5 beneficial soil bacteria that convey the specific plant benefits mentioned above. Contact Custom for more information. 

Soil Quality using Management Practices

Soil Quality using Management Practices

Soil quality is the most important factor for long term agricultural productivity . A good soil manager will monitor the organic content of the soil, water holding capacity, and a host of other soil quality parameters that are discussed in detail in the article below. 

Soil quality also relies on the diversity of beneficial soil microorganisms.

Wise management practices could improve soil quality

 

Surface soil produces our food and is vital for life. This precious resource often is called “skin of the Earth” and, just as skin, it is important to protect and maintain its quality.

Soil quality is the inherent capacity of a particular soil to support human health and habitation; maintain or enhance air and water quality; and, most important, sustain plant and animal productivity.

From an agricultural standpoint, soil quality is vital for improving long-term agricultural productivity and maximizing profits through sustainable productivity.

It is important for soil both to function optimally for current needs and remain healthy for future use. Soil organic matter, tillage, soil compaction, soil structure, depth of soil, water-holding capacity, electrical conductivity, pH, ground cover, microbial biodiversity, carbon-to-nitrogen ratio and nutrient management are some of the important parameters of soil quality.

Improving and maintaining soil organic matter content is the most important quality parameter. Increasing organic matter improves soil structure as well as water- and nutrient-holding capacity, supports soil microbes, and protects soil from erosion and compaction. Organic matter can be improved by using no-till or minimum till methods, growing cover crops, leaving crop residues and using rotations with crops that balance optimal water and nutrient management practices.

Using reduced tillage practices will protect the soil surface, which decreases soil erosion and soil compaction, and decreases the loss of organic matter. Reduction in tillage also decreases the potential for destroying soil structure. Soil compaction can be caused by using heavy equipment on the surface when the soil is wet. Compaction will reduce the amount of air, water and pore space for growth of both soil microbes and plant roots. Soil compaction can be reduced by minimizing equipment use when the ground is wet and combining multiple farm tasks, such as applying both herbicides and fertilizer in one trip.

Growing cover crops and leaving residue from previous crops is the best way to reduce soil erosion by wind and water. Ground cover can be increased by growing perennial crops such as grasses in a pasture situation. Ground cover will improve water availability, but care should be taken to manage it properly to prevent disease outbreak.

Soil quality also relies on microbial organisms. Diversity in soil microbes may be helpful in controlling pest populations, diseases and weeds. Biodiversity can be achieved by increasing long-term crop rotations, since each plant in rotation contributes to unique soil structure and plant residue.

Understanding how to improve soil quality is aided by knowledge of the carbon-to-nitrogen (C:N) ratio for managing cover crops and nutrient cycling.

The C:N ratio is the amount of carbon to the amount of nitrogen in a residue or other organic material applied to soil. If material with a higher C:N ratio residue is applied, it takes longer to decompose and may immobilize inorganic fertilizers that are applied. This problem can be reduced by growing a low C:N ratio crop (e.g., vetch or other legumes) in rotation with a high C:N ratio crop (e.g., wheat straw).

Finally, efficient nutrient management is important in maintaining soil quality. Test your soils regularly and make sure that you store all your records. Examining records over time will tell whether the management practices that were followed increased or depleted soil nutrients. Too much fertilizer or manure may cause groundwater contamination or may run off and enter water bodies and degrade water quality. Application of nutrients based on a soil test will alleviate this problem.

What works on one farm may not work on another. Adjust your management plan by observing changes in soil quality on your farm. Wise management decisions will improve the overall quality of the soil. Being proactive, rather than reactive, will make you a better steward of this limited resource.

 

 

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Sustainable Farming Practices

Sustainable Farming Practices

 

Sustainable farming practices are in the news these days. This article talks about sustainable farming practices from a pragmatic point of view.

The definition of sustainable farming is practical as well: “a group of practices designed to protect the earth from potential harm that growing crops and animals for food sustainable farming practicespurposes can do”.

 

If you’re involved in agriculture, even on a small scale, chances are you’ve heard about sustainable farming practices before. On the off chance that you haven’t, sustainable farming, simply put, is a group of practices designed to protect the earth from potential harm that growing crops and raising animals for food purposes can do.

However, for many farmers, sustainable farming seems like an unreachable goal, and one that will make day-to-day operations too costly. While that may be true of very expensive processes that involve full-scale renovations to a farm or growing land, there are many sustainable farming practices that can be easily incorporated into your regular routine.

In fact, some can even save you money in the long run.

 

Water Management

Poorly maintained irrigation systems and water waste are common problems among farms of all sizes, from small single-family farms to major farms that supply significant amounts of food for resale; however, managing your water consumption doesn’t have to be a chore.

The easiest and best way to manage your water use is by planting crops that naturally grow in the area. If you live in an area without a lot of rain, don’t plant crops that need considerable moisture on a regular basis in large quantities.

In addition to choosing the proper crops, irrigating your land properly and using cover crops that help the soil retain moisture for longer periods of time, therefore requiring less watering from you, can help reduce your overall water use.

Collecting rainwater is another option for many farmers, and that can save you money after your initial investment is paid back within a relatively short period of time.

 

Rotate Your Crops

Crop rotation is an old practice that teaches farmers to alternate their crops in order to keep their soil as healthy and nutrient-rich as possible. In some cases, crop rotation can be very simple.

For example, you should plant grains after legumes and crops that grow in rows after grains; however, depending on what you’re growing, it isn’t always that simple. Doing a little bit of homework on how to best rotate your specific crops is recommended.

The benefits of rotating your crops include prevention of disease transmission from crop to crop and a general reduction in the amount of pests in the soil that can damage crops.

 

Diversify Your Crops

Crop diversity takes the idea of crop rotation a step further, getting farmers to alternate the species of a certain type of crop when they grow it. This not only helps to keep soil nutrient-rich, but it also helps farmers protect their crops from diseases and pests.

Using a combination crop rotation and crop diversification method is ideal, and if you’re only growing a handful of crops each year, it is surprisingly simple to do.

 

Controlled Pest Management

Pest management is a serious concern for many farmers; however, simply spraying all of your crops isn’t in the best interest for the soil, your crops or the earth, and it doesn’t have to be done if you’re smart about how you plant your crops.

By rotating crops, diversifying your species and integrating beneficial insects that keep harmful pests out, you may not need to spray at all. If you do, you’ll be able to use a targeted-spray method, limiting your overall use of pesticides and chemicals.

Sustainable farming is more important today than it ever has been because of droughts in many areas and increased temperatures all over the globe. Even if you only grow a small amount of crops each year, using these basic sustainable growing practices can help reduce your farm’s environmental impact while saving you money in the process.

 

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Crop rotation and the role of microorganisms

Crop rotation has been used effectively  for centuries; however, this is the first article that I have seen that discusses the changes in the microorganisms in the soil as a result of the rotation.

It’s probably not surprising that the organisms changed. What surprised me was that with the wheat the soil microorganisms were mostly bacteria. When crops the crops were changes to oats or peas, there was a shift to soil fungi.

I’d expect to see more studies about the role of microorganisms in the soil in the future. As we move towards using less fertilizer and towards sustainable agricultural practices the role of microorganisms may well be the key feature.

 

 

Crop rotation and the role of microorganisms

Crop rotation has been used since ancient times to improve plant nutrition and to limit the spread of disease. A new study reveals this relates to enriching the soil with bacteria, fungi and protozoa.

Crop rotation is the practice of growing a series of different types of crops in the same area in sequential seasons. The practice of crop rotation gives various benefits to the soil, such as the replenishment of nitrogen.

In essence, the new research has demonstrated that changing the crop species massively changes the content of microbes in the soil, which in turn helps the plant to acquire nutrients, regulate growth and protect itself against pests and diseases, boosting yield. The location where this happens is called the rhizosphere. The rhizosphere is the narrow region of soil that is directly influenced by root secretions and associated soil microorganisms.

To show this an organic agricultural study was conducted. Soil was collected from a field near Norwich (in the U.K.) and planted with wheat, oats and peas. After growing wheat, the analysis of the soil showed that it remained largely unchanged and the microbes in it were mostly bacteria. However, growing oat and pea in the same soil caused a huge shift towards fungi.

To show this, extensive genetic testing was required because each gram of soil contains over 50,000 species of bacteria. The findings of the study could be used to develop plant varieties that encourage beneficial microbes in the soil.

The study was published in Nature’s The ISME Journal. The paper is titled “Comparative metatranscriptomics reveals kingdom level changes in the rhizosphere microbiome of plants.”

Read more: http://www.digitaljournal.com/article/355178#ixzz2aAkc91md

 

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