Pcb Terminal


Todays deals on Pcb Terminal?

eBay Logo  

FANUC TERMINAL INTERFACE MAIN CPU PCB A20B-2100-0690


FANUC TERMINAL INTERFACE MAIN CPU PCB A20B-2100-0690


$600.00


G.H.GROUP CXS2.2 RELEBONDING I/O TERMINAL PCB BOARD GH


G.H.GROUP CXS2.2 RELEBONDING I/O TERMINAL PCB BOARD GH


$290.00


PCB ANALOG J-BOX 13640300A METTLER TOLEDO TERMINAL JUNCTION PC BOARD NEW!


PCB ANALOG J-BOX 13640300A METTLER TOLEDO TERMINAL JUNCTION PC BOARD NEW!


$249.98


1000pcs PCB Terminal Block  WJ305-5.0mm-2P RoHS


1000pcs PCB Terminal Block WJ305-5.0mm-2P RoHS


$150.00


pcb screw terminal block WJ301 5mm 3PIN-1000PCS UL CE RoHS DHL FREE SHIPPING


pcb screw terminal block WJ301 5mm 3PIN-1000PCS UL CE RoHS DHL FREE SHIPPING


$225.00


PCB terminal block WJ306 5.0mm 3PIN-1000PCS UL CE RoHS DHL FREE SHIPPING


PCB terminal block WJ306 5.0mm 3PIN-1000PCS UL CE RoHS DHL FREE SHIPPING


$220.00


PCB terminal block WJ350 3.5mm 3PIN-1000PCS UL CE RoHS DHL FEDEX FREE SHIPPING


PCB terminal block WJ350 3.5mm 3PIN-1000PCS UL CE RoHS DHL FEDEX FREE SHIPPING


$220.00


PCB terminal blocks WJ350-3.5mm- 3PIN-1000PCS  CE RoHS DHL FEDEX FREE SHIPPING


PCB terminal blocks WJ350-3.5mm- 3PIN-1000PCS CE RoHS DHL FEDEX FREE SHIPPING


$220.00


PCB terminal blocks WJ103-5.0mm- 3PIN-1000PCS  CE RoHS DHL FEDEX FREE SHIPPING


PCB terminal blocks WJ103-5.0mm- 3PIN-1000PCS CE RoHS DHL FEDEX FREE SHIPPING


$220.00


PCB terminal block WJ396 3.96mm pitch 3PIN-1000PCS UL CE RoHS DHL FREE SHIPPING


PCB terminal block WJ396 3.96mm pitch 3PIN-1000PCS UL CE RoHS DHL FREE SHIPPING


$220.00


AMP Tyco 62650-1 Quick Disconnect FASTON PCB Tab Terminal/Contact Reel 6000


AMP Tyco 62650-1 Quick Disconnect FASTON PCB Tab Terminal/Contact Reel 6000


$189.95


PCB terminal block WJ306 5.0mm 2PIN-1000PCS UL CE RoHS DHL FREE SHIPPING


PCB terminal block WJ306 5.0mm 2PIN-1000PCS UL CE RoHS DHL FREE SHIPPING


$160.00


100 pcs 5.08mm Pitch 300V 16A 8P Poles PCB Screw Terminal Block Connector Green


100 pcs 5.08mm Pitch 300V 16A 8P Poles PCB Screw Terminal Block Connector Green


$159.88


100 8 Pin 5.08mm PCB Universal Screw Terminal Block Connector 300V 16A GSP001 RC


100 8 Pin 5.08mm PCB Universal Screw Terminal Block Connector 300V 16A GSP001 RC


$159.88


100 8 Pin 5.08mm PCB Universal Screw Terminal Block Connector 300V 16A GSP001 RC


100 8 Pin 5.08mm PCB Universal Screw Terminal Block Connector 300V 16A GSP001 RC


$159.88


RepRap Sanguinololu 1.3a PCB DIY or Built and tested A4988 3D Printer Controller


RepRap Sanguinololu 1.3a PCB DIY or Built and tested A4988 3D Printer Controller


$146.14


PCB terminal block WJ396 3.96mm 2PIN-1000PCS UL CE RoHS DHL FREE SHIPPING


PCB terminal block WJ396 3.96mm 2PIN-1000PCS UL CE RoHS DHL FREE SHIPPING


$150.00


PCB terminal block WJ396 3.96mm 3PIN-1000PCS UL CE RoHS DHL FREE SHIPPING


PCB terminal block WJ396 3.96mm 3PIN-1000PCS UL CE RoHS DHL FREE SHIPPING


$150.00


 PCB terminal block WJ301 5mm 2PIN-1000PCS UL CE RoHS DHL FEDEX FREE SHIPPING


PCB terminal block WJ301 5mm 2PIN-1000PCS UL CE RoHS DHL FEDEX FREE SHIPPING


$150.00


PCB terminal block WJ350 3.5mm 2PIN-1000PCS UL CE RoHS DHL FREE SHIPPING


PCB terminal block WJ350 3.5mm 2PIN-1000PCS UL CE RoHS DHL FREE SHIPPING


$150.00


PCB terminal blocks WJ103-5.0mm- 2PIN-1000PCS  CE RoHS DHL FEDEX FREE SHIPPING


PCB terminal blocks WJ103-5.0mm- 2PIN-1000PCS CE RoHS DHL FEDEX FREE SHIPPING


$150.00


100pcs 12 Poles 2.54mm/0.1


100pcs 12 Poles 2.54mm/0.1″ PCB Universal Screw Terminal Block


$148.00


500xKF332 PCB Mount Terminal Block Connector 5.0 mm ca-ttc0n2


500xKF332 PCB Mount Terminal Block Connector 5.0 mm ca-ttc0n2


$120.00


100 Relay Socket OMRON PT08-0 8pin PCB solder Terminal LY2


100 Relay Socket OMRON PT08-0 8pin PCB solder Terminal LY2


$112.50


100pcs 10 Poles 2.54mm/0.1


100pcs 10 Poles 2.54mm/0.1″ PCB Universal Screw Terminal Block


$125.00


200 pcs 5.08mm Pitch 300V 16A 3P Poles PCB Screw Terminal Block Connector Green


200 pcs 5.08mm Pitch 300V 16A 3P Poles PCB Screw Terminal Block Connector Green


$122.93


200 3 Pin 5.08mm PCB Universal Screw Terminal Block Connector 300V 16A GSP001 RC


200 3 Pin 5.08mm PCB Universal Screw Terminal Block Connector 300V 16A GSP001 RC


$122.93


NEW 50 Phoenix Contact 1752399 5 Terminal Block Printed Circuit Board Connector


NEW 50 Phoenix Contact 1752399 5 Terminal Block Printed Circuit Board Connector


$119.79


100 pcs 5.08mm Pitch 300V 16A 6P Poles PCB Screw Terminal Block Connector Green


100 pcs 5.08mm Pitch 300V 16A 6P Poles PCB Screw Terminal Block Connector Green


$116.88


100 6 Pin 5.08mm PCB Universal Screw Terminal Block Connector 300V 16A GSP001 RC


100 6 Pin 5.08mm PCB Universal Screw Terminal Block Connector 300V 16A GSP001 RC


$116.88


100 6 Pin 5.08mm PCB Universal Screw Terminal Block Connector 300V 16A GSP001 RC


100 6 Pin 5.08mm PCB Universal Screw Terminal Block Connector 300V 16A GSP001 RC


$116.88


$.10 A SCREW ...TYCO SCREW TERMINAL PCB MOUT 1X10 5.08mm .200


$.10 A SCREW …TYCO SCREW TERMINAL PCB MOUT 1X10 5.08mm .200″ Qty100 in one lot


$99.95


100pcs 9 Poles 2.54mm/0.1


100pcs 9 Poles 2.54mm/0.1″ PCB Universal Screw Terminal Block


$112.00


WEIDMULLER 998576/67 PCB TERMINAL AND CONNECTOR


WEIDMULLER 998576/67 PCB TERMINAL AND CONNECTOR


$99.99


1x4 PCB Screw Terminal .200 mil 5.08mm spacing  Qty 100


1×4 PCB Screw Terminal .200 mil 5.08mm spacing Qty 100


$89.95


RepRap Sanguinololu 1.3a PCB DIY or Built and tested A4988 3D Printer Controller


RepRap Sanguinololu 1.3a PCB DIY or Built and tested A4988 3D Printer Controller


$91.15


TYCO 796949-2 Terminal PCB 1x2 5.08mm .200sp Qty 250


TYCO 796949-2 Terminal PCB 1×2 5.08mm .200sp Qty 250


$89.95


100pcs 8 Poles 2.54mm/0.1


100pcs 8 Poles 2.54mm/0.1″ PCB Universal Screw Terminal Block


$95.00


100pcs 7 Poles 2.54mm/0.1


100pcs 7 Poles 2.54mm/0.1″ PCB Universal Screw Terminal Block


$88.00


500pcs 2-Way PCB Panel Terminal Block Socket 5mm,2301


500pcs 2-Way PCB Panel Terminal Block Socket 5mm,2301


$85.00


500pcs 2-Way PCB Panel Terminal Block Socket 5mm,2301


500pcs 2-Way PCB Panel Terminal Block Socket 5mm,2301


$85.00


500pcs 2-Way PCB Panel Terminal Block Socket 5mm,2301


500pcs 2-Way PCB Panel Terminal Block Socket 5mm,2301


$85.00


200 pcs 5.08mm Pitch 300V 16A 2P Poles PCB Screw Terminal Block Connector Green


200 pcs 5.08mm Pitch 300V 16A 2P Poles PCB Screw Terminal Block Connector Green


$82.77


200 2 Pin 5.08mm PCB Universal Screw Terminal Block Connector 300V 16A GSP001 RC


200 2 Pin 5.08mm PCB Universal Screw Terminal Block Connector 300V 16A GSP001 RC


$82.77


3 Poles 7.5mm PCB Universal Screw Terminal Block, x200


3 Poles 7.5mm PCB Universal Screw Terminal Block, x200


$82.00


200pcs 3 Poles 2.54mm/0.1


200pcs 3 Poles 2.54mm/0.1″ PCB Universal Screw Terminal Block


$82.00


50 pcs 5.08mm Pitch 300V 16A 8P Poles PCB Screw Terminal Block Connector Green


50 pcs 5.08mm Pitch 300V 16A 8P Poles PCB Screw Terminal Block Connector Green


$81.88


50x 8 Pin 5.08mm PCB Universal Screw Terminal Block Connector 300V 16A GSP001 RC


50x 8 Pin 5.08mm PCB Universal Screw Terminal Block Connector 300V 16A GSP001 RC


$81.88


50x 8 Pin 5.08mm PCB Universal Screw Terminal Block Connector 300V 16A GSP001 RC


50x 8 Pin 5.08mm PCB Universal Screw Terminal Block Connector 300V 16A GSP001 RC


$81.88


200 pcs 2.54mm Pitch 150V 6A 3P Poles PCB Screw Terminal Block Connector Green


200 pcs 2.54mm Pitch 150V 6A 3P Poles PCB Screw Terminal Block Connector Green


$79.88


200 pcs 3 Pin 2.54mm PCB Universal Screw Terminal Block Connector 300V 6A GS019S


200 pcs 3 Pin 2.54mm PCB Universal Screw Terminal Block Connector 300V 6A GS019S


$79.88


200 x  3 Pin 2.54mm PCB Universal Screw Terminal Block Connector 300V 6A GS019S


200 x 3 Pin 2.54mm PCB Universal Screw Terminal Block Connector 300V 6A GS019S


$79.88


3 Poles 5.0mm PCB Universal Screw Terminal Block, x200


3 Poles 5.0mm PCB Universal Screw Terminal Block, x200


$79.00


New Surplus Keyence OP-42372  OP42372 PC Module w/9 pt Terminal Connection PCB


New Surplus Keyence OP-42372 OP42372 PC Module w/9 pt Terminal Connection PCB


$79.00


100 pcs 5.08mm Pitch 300V 16A 4P Poles PCB Screw Terminal Block Connector Green


100 pcs 5.08mm Pitch 300V 16A 4P Poles PCB Screw Terminal Block Connector Green


$75.23


100 4 Pin 5.08mm PCB Universal Screw Terminal Block Connector 300V 16A GSP001 RC


100 4 Pin 5.08mm PCB Universal Screw Terminal Block Connector 300V 16A GSP001 RC


$75.23


100 4 Pin 5.08mm PCB Universal Screw Terminal Block Connector 300V 16A GSP001 RC


100 4 Pin 5.08mm PCB Universal Screw Terminal Block Connector 300V 16A GSP001 RC


$75.23


3 Poles 3.81mm PCB Universal Screw Terminal Block, x200


3 Poles 3.81mm PCB Universal Screw Terminal Block, x200


$75.00


100pcs 6 Poles 2.54mm/0.1


100pcs 6 Poles 2.54mm/0.1″ PCB Universal Screw Terminal Block


$73.00


2 Poles 7.5mm PCB Universal Screw Terminal Block, x200


2 Poles 7.5mm PCB Universal Screw Terminal Block, x200


$72.00


200pcs 2 Poles 2.54mm/0.1


200pcs 2 Poles 2.54mm/0.1″ PCB Universal Screw Terminal Block


$72.00


200 pcs 2.54mm Pitch 150V 6A 2P Poles PCB Screw Terminal Block Connector Green


200 pcs 2.54mm Pitch 150V 6A 2P Poles PCB Screw Terminal Block Connector Green


$69.88


200 pcs 2 Pin 2.54mm PCB Universal Screw Terminal Block Connector 300V 6A GS019S


200 pcs 2 Pin 2.54mm PCB Universal Screw Terminal Block Connector 300V 6A GS019S


$69.88


200 x 2 Pin 2.54mm PCB Universal Screw Terminal Block Connector 300V 6A GS019S


200 x 2 Pin 2.54mm PCB Universal Screw Terminal Block Connector 300V 6A GS019S


$69.88


RepRap Sanguinololu 1.3a PCB DIY or Built and tested A4988 3D Printer Controller


RepRap Sanguinololu 1.3a PCB DIY or Built and tested A4988 3D Printer Controller


$56.56


2 Poles 5.0mm PCB Universal Screw Terminal Block, x200


2 Poles 5.0mm PCB Universal Screw Terminal Block, x200


$68.00


200 pcs 5mm Pitch 300V 16A 3P Poles PCB Screw Terminal Block Connector Blue


200 pcs 5mm Pitch 300V 16A 3P Poles PCB Screw Terminal Block Connector Blue


$67.59


200 x 3 Pin 5mm PCB Universal Screw Terminal Block Connector 300V 16A GS002S


200 x 3 Pin 5mm PCB Universal Screw Terminal Block Connector 300V 16A GS002S


$67.59


200x 3 Pin 5mm PCB Universal Screw Terminal Block Connector 300V 16A GS002S Blue


200x 3 Pin 5mm PCB Universal Screw Terminal Block Connector 300V 16A GS002S Blue


$67.59


RepRap Sanguinololu 1.3a PCB DIY or Built and tested A4988 3D Printer Controller


RepRap Sanguinololu 1.3a PCB DIY or Built and tested A4988 3D Printer Controller


$53.42


Potter & Brumfield 2IOQ24 I/O Relay Mounting Board 24 Terminal Positions PCB


Potter & Brumfield 2IOQ24 I/O Relay Mounting Board 24 Terminal Positions PCB


$64.99


100pcs 5 Poles 2.54mm/0.1


100pcs 5 Poles 2.54mm/0.1″ PCB Universal Screw Terminal Block


$64.00


2 Poles 3.81mm PCB Universal Screw Terminal Block, x200


2 Poles 3.81mm PCB Universal Screw Terminal Block, x200


$64.00


50pc PCB Terminal Block GGB-40-08 A04P 4P 10mm 20A300V


50pc PCB Terminal Block GGB-40-08 A04P 4P 10mm 20A300V


$35.80


100 pcs 3 Pin 9.5mm PCB Universal Screw Terminal Block Connector 300V 30A GS008S


100 pcs 3 Pin 9.5mm PCB Universal Screw Terminal Block Connector 300V 30A GS008S


$63.34


100 x 3 Pin 9.5mm PCB Universal Screw Terminal Block Connector 300V 30A GS008


100 x 3 Pin 9.5mm PCB Universal Screw Terminal Block Connector 300V 30A GS008


$63.34


100 pcs 9.5mm Pitch 300V 30A 3P Poles PCB Screw Terminal Block Connector Green


100 pcs 9.5mm Pitch 300V 30A 3P Poles PCB Screw Terminal Block Connector Green


$63.34


100 pcs 5.08mm Pitch 300V 16A 3P Poles PCB Screw Terminal Block Connector Green


100 pcs 5.08mm Pitch 300V 16A 3P Poles PCB Screw Terminal Block Connector Green


$62.70


100 3 Pin 5.08mm PCB Universal Screw Terminal Block Connector 300V 16A GSP001 RC


100 3 Pin 5.08mm PCB Universal Screw Terminal Block Connector 300V 16A GSP001 RC


$62.70


100 3 Pin 5.08mm PCB Universal Screw Terminal Block Connector 300V 16A GSP001 RC


100 3 Pin 5.08mm PCB Universal Screw Terminal Block Connector 300V 16A GSP001 RC


$62.70


200x 2 Pin 5mm PCB Universal Screw Terminal Block Connector 300V 16A GS002S Blue


200x 2 Pin 5mm PCB Universal Screw Terminal Block Connector 300V 16A GS002S Blue


$61.65


200 pcs 5mm Pitch 300V 16A 2P Poles PCB Screw Terminal Block Connector Blue


200 pcs 5mm Pitch 300V 16A 2P Poles PCB Screw Terminal Block Connector Blue


$61.56


200 x 2 Pin 5mm PCB Universal Screw Terminal Block Connector 300V 16A GS002S


200 x 2 Pin 5mm PCB Universal Screw Terminal Block Connector 300V 16A GS002S


$61.56


PREMIER PNEUMATICS 2139-7 TERMINAL CONNECT PCB ***XLNT***


PREMIER PNEUMATICS 2139-7 TERMINAL CONNECT PCB ***XLNT***


$49.00


50 pcs 5.08mm Pitch 300V 16A 6P Poles PCB Screw Terminal Block Connector Green


50 pcs 5.08mm Pitch 300V 16A 6P Poles PCB Screw Terminal Block Connector Green


$58.88


50x 6 Pin 5.08mm PCB Universal Screw Terminal Block Connector 300V 16A GSP001 RC


50x 6 Pin 5.08mm PCB Universal Screw Terminal Block Connector 300V 16A GSP001 RC


$58.88


CX0400/0501 TERMINAL BLOCK PCB 45 DEGREE 4WAY - 10 Pack


CX0400/0501 TERMINAL BLOCK PCB 45 DEGREE 4WAY – 10 Pack


$1.57


TERMINAL PCB 1X7  Wire Top Entry 20A 300V Vertical


TERMINAL PCB 1X7 Wire Top Entry 20A 300V Vertical


$47.95


100pcs 4 Poles 2.54mm/0.1


100pcs 4 Poles 2.54mm/0.1″ PCB Universal Screw Terminal Block


$55.00


WECO Terminal PCB 1x6 Screw Rt Ang 5mm Spacing Qty 100


WECO Terminal PCB 1×6 Screw Rt Ang 5mm Spacing Qty 100


$44.95


100pc PCB Terminal Block GGB-40-07 B02P 2P 10mm 20A300V


100pc PCB Terminal Block GGB-40-07 B02P 2P 10mm 20A300V


$25.60


PHOENIX CONTACT 1715048 MKDS 1.5/4  PCB terminal (50)


PHOENIX CONTACT 1715048 MKDS 1.5/4 PCB terminal (50)


$48.00


20 x 3 Pin 10.16mm PCB Universal Screw Terminal Block Connector 600V 50A GS031


20 x 3 Pin 10.16mm PCB Universal Screw Terminal Block Connector 600V 50A GS031


$50.60


20 pcs 10.16mm Pitch 600V 50A 3P Poles PCB Screw Terminal Block Connector Green


20 pcs 10.16mm Pitch 600V 50A 3P Poles PCB Screw Terminal Block Connector Green


$50.60


50pc PCB Terminal Block GGB-40-08 A03P 3P 10mm 20A300V


50pc PCB Terminal Block GGB-40-08 A03P 3P 10mm 20A300V


$27.50


Molex 0398600302 5.08mm Pitch Beau Eurostyle Pluggable PCB Terminal Block (120)


Molex 0398600302 5.08mm Pitch Beau Eurostyle Pluggable PCB Terminal Block (120)


$49.99


30x 8 Pin 5.08mm PCB Universal Screw Terminal Block Connector 300V 16A GSP001 RC


30x 8 Pin 5.08mm PCB Universal Screw Terminal Block Connector 300V 16A GSP001 RC


$49.88


30 pcs 5.08mm Pitch 300V 16A 8P Poles PCB Screw Terminal Block Connector Green


30 pcs 5.08mm Pitch 300V 16A 8P Poles PCB Screw Terminal Block Connector Green


$49.88


30x 8 Pin 5.08mm PCB Universal Screw Terminal Block Connector 300V 16A GSP001 RC


30x 8 Pin 5.08mm PCB Universal Screw Terminal Block Connector 300V 16A GSP001 RC


$49.88


100 pcs 5.08mm Pitch 300V 16A 2P Poles PCB Screw Terminal Block Connector Green


100 pcs 5.08mm Pitch 300V 16A 2P Poles PCB Screw Terminal Block Connector Green


$46.62

Pcb Terminal Questions

Pcb Terminal

Cover Crop

Soil fertility management

Main article: Green manure

One of the primary uses of cover crops is to increase soil fertility. These types of cover crops are referred to as “green manure.” They are used to manage a range of soil macronutrients and micronutrients. Of the various nutrients, the impact that cover crops have on nitrogen management has received the most attention from researchers and farmers, because nitrogen is often the most limiting nutrient in crop production.

Often, green manure crops are grown for a specific period, and then plowed under before reaching full maturity in order to improve soil fertility and quality.

Green manure crops are commonly leguminous, meaning they are part of the Fabaceae (pea) family. This family is unique in that all of the species in it set pods, such as bean, lentil, lupins and alfalfa. Leguminous cover crops are typically high in nitrogen and can often provide the required quantity of nitrogen for crop production. Normally, this nitrogen would be applied in chemical fertilizer form. This quality of cover crops is called fertilizer replacement value (Thiessen-Martens et al. 2005).

Another quality unique to leguminous cover crops is that they form symbiotic relationships with the rhizobial bacteria that reside in legume root nodules. Lupins is nodulated by the soil microorganism Bradyrhizobium sp. (Lupinus). Bradyrhizobia are encountered as microsymbionts in other leguminous crops (Argyrolobium, Lotus, Ornithopus, Acacia, Lupinus) of Mediterranean origin. These bacteria convert biologically unavailable atmospheric nitrogen gas (N2) to biologically available mineral nitrogen (NH4+) through the process of biological nitrogen fixation.

Prior to the advent of the Haber-Bosch process, an energy-intensive method developed to carry out industrial nitrogen fixation and create chemical nitrogen fertilizer, most nitrogen introduced to ecosystems arose through biological nitrogen fixation (Galloway et al. 1995). Some scientists believe that widespread biological nitrogen fixation, achieved mainly through the use of cover crops, is the only alternative to industrial nitrogen fixation in the effort to maintain or increase future food production levels (Bohlool et al. 1992, Peoples and Craswell 1992, Giller and Cadisch 1995). Industrial nitrogen fixation has been criticized as an unsustainable source of nitrogen for food production due to its reliance on fossil fuel energy and the environmental impacts associated with chemical nitrogen fertilizer use in agriculture (Jensen and Hauggaard-Nielsen 2003). Such widespread environmental impacts include nitrogen fertilizer losses into waterways, which can lead to eutrophication (nutrient loading) and ensuing hypoxia (oxygen depletion) of large bodies of water.

An example of this lies in the Mississippi Valley Basin, where years of fertilizer nitrogen loading into the watershed from agricultural production have resulted in a hypoxic ead zone off the Gulf of Mexico the size of New Jersey (Rabalais et al. 2002). The ecological complexity of marine life in this zone has been diminishing as a consequence (CENR 2000).

As well as bringing nitrogen into agroecosystems through biological nitrogen fixation, types of cover crops known as atch crops are used to retain and recycle soil nitrogen already present. The catch crops take up surplus nitrogen remaining from fertilization of the previous crop, preventing it from being lost through leaching (Morgan et al. 1942), or gaseous denitrification or volatilization (Thorup-Kristensen et al. 2003).

Catch crops are typically fast-growing annual cereal species adapted to scavenge available nitrogen efficiently from the soil (Ditsch and Alley 1991). The nitrogen tied up in catch crop biomass is released back into the soil once the catch crop is incorporated as a green manure or otherwise begins to decompose

An example of green manure use comes from Nigeria, where the cover crop Mucuna pruriens (velvet bean) has been found to increase the availability of phosphorus in soil after a farmer applies rock phosphate (Vanlauwe et al. 2000).

Soil quality management

Cover crops can also improve soil quality by increasing soil organic matter levels through the input of cover crop biomass over time. Increased soil organic matter enhances soil structure, as well as the water and nutrient holding and buffering capacity of soil (Patrick et al. 1957). It can also lead to increased soil carbon sequestration, which has been promoted as a strategy to help offset the rise in atmospheric carbon dioxide levels (Kuo et al. 1997, Sainju et al. 2002, Lal 2003).

Although cover crops can perform multiple functions in an agroecosystem simultaneously, they are often grown for the sole purpose of preventing soil erosion. Soil erosion is a process that can irreparably reduce the productive capacity of an agroecosystem. Dense cover crop stands physically slow down the velocity of rainfall before it contacts the soil surface, preventing soil splashing and erosive surface runoff (Romkens et al. 1990). Additionally, vast cover crop root networks help anchor the soil in place and increase soil porosity, creating suitable habitat networks for soil macrofauna (Tomlin et al. 1995).

Soil quality is managed to produce optimum circumstances for crops to flourish. The principal factors of soil quality are soil salination, pH, microorganism balance and the prevention of soil contamination.

Water management

By reducing soil erosion, cover crops often also reduce both the rate and quantity of water that drains off the field, which would normally pose environmental risks to waterways and ecosystems downstream (Dabney et al. 2001). Cover crop biomass acts as a physical barrier between rainfall and the soil surface, allowing raindrops to steadily trickle down through the soil profile. Also, as stated above, cover crop root growth results in the formation of soil pores, which in addition to enhancing soil macrofauna habitat provides pathways for water to filter through the soil profile rather than draining off the field as surface flow. With increased water infiltration, the potential for soil water storage and the recharging of aquifers can be improved (Joyce et al. 2002).

Just before cover crops are killed (by such practices including mowing, tilling, discing, rolling, or herbicide application) they contain a large amount of moisture. When the cover crop is incorporated into the soil, or left on the soil surface, it often increases soil moisture. In agroecosystems where water for crop production is in short supply, cover crops can be used as a mulch to conserve water by shading and cooling the soil surface. This reduces evaporation of soil moisture. In other situations farmers try to dry the soil out as quickly as possible going into the planting season. Here prolonged soil moisture conservation can be problematic.

While cover crops can help to conserve water, in temperate regions (particularly in years with below average precipitation) they can draw down soil water supply in the spring, particularly if climatic growing conditions are good. In these cases, just before crop planting, farmers often face a tradeoff between the benefits of increased cover crop growth and the drawbacks of reduced soil moisture for cash crop production that season.

Weed management

Thick cover crop stands often compete well with weeds during the cover crop growth period, and can prevent most germinated weed seeds from completing their life cycle and reproducing. If the cover crop is left on the soil surface rather than incorporated into the soil as a green manure after its growth is terminated, it can form a nearly impenetrable mat. This drastically reduces light transmittance to weed seeds, which in many cases reduces weed seed germination rates (Teasdale 1993). Furthermore, even when weed seeds germinate, they often run out of stored energy for growth before building the necessary structural capacity to break through the cover crop mulch layer. This is often termed the cover crop smother effect (Kobayashi et al. 2003).

Some cover crops suppress weeds both during growth and after death (Blackshaw et al. 2001). During growth these cover crops compete vigorously with weeds for available space, light, and nutrients, and after death they smother the next flush of weeds by forming a mulch layer on the soil surface. For example, Blackshaw et al. (2001) found that when using Melilotus officinalis (yellow sweetclover) as a cover crop in an improved fallow system (where a fallow period is intentionally improved by any number of different management practices, including the planting of cover crops), weed biomass only constituted between 1-12% of total standing biomass at the end of the cover crop growing season. Furthermore, after cover crop termination, the yellow sweetclover residues suppressed weeds to levels 75-97% lower than in fallow (no yellow sweetclover) systems .

In addition to competition-based or physical weed suppression, certain cover crops are known to suppress weeds through allelopathy (Creamer et al. 1996, Singh et al. 2003). This occurs when certain biochemical cover crop compounds are degraded that happen to be toxic to, or inhibit seed germination of, other plant species. Some well known examples of allelopathic cover crops are Secale cereale (rye), Vicia villosa (hairy vetch), Trifolium pratense (red clover), Sorghum bicolor (sorghum-sudangrass), and species in the brassicaceae family, particularly mustards (Haramoto and Gallandt 2004). In one study, rye cover crop residues were found to have provided between 80% and 95% control of early season broadleaf weeds when used as a mulch during the production of different cash crops such as soybean, tobacco, corn, and sunflower (Nagabhushana et al. 2001).

Disease management

In the same way that allelopathic properties of cover crops can suppress weeds, they can also break disease cycles and reduce populations of bacterial and fungal diseases (Everts 2002), and parasitic nematodes (Potter et al. 1998, Vargas-Ayala et al. 2000). Species in the brassicaceae family, such as mustards, have been widely shown to suppress fungal disease populations through the release of naturally occurring toxic chemicals during the degradation of glucosinolade compounds in their plant cell tissues (Lazzeri and Manici 2001).

Pest management

Some cover crops are used as so-called “trap crops”, to attract pests away from the crop of value and toward what the pest sees as a more favorable habitat (Shelton and Badenes-Perez 2006). Trap crop areas can be established within crops, within farms, or within landscapes. In many cases the trap crop is grown during the same season as the food crop being produced. The limited area occupied by these trap crops can be treated with a pesticide once pests are drawn to the trap in large enough numbers to reduce the pest populations. In some organic systems, farmers drive over the trap crop with a large vacuum-based implement to physically pull the pests off the plants and out of the field (Kuepper and Thomas 2002). This system has been recommended for use to help control the lygus bugs in organic strawberry production (Zalom et al. 2001).

Other cover crops are used to attract natural predators of pests by providing elements of their habitat. This is a form of biological control known as habitat augmentation, but achieved with the use of cover crops (Bugg and Waddington 1994). Findings on the relationship between cover crop presence and predator/pest population dynamics have been mixed, pointing toward the need for detailed information on specific cover crop types and management practices to best complement a given integrated pest management strategy. For example, the predator mite Euseius tularensis (Congdon) is known to help control the pest citrus thrips in Central California citrus orchards. Researchers found that the planting of several different leguminous cover crops (such as bell bean, woollypod vetch, New Zealand white clover, and Austrian winter pea) provided sufficient pollen as a feeding source to cause a seasonal increase in Congdon populations, which with good timing could potentially introduce enough predatory pressure to reduce pest populations of citrus thrips (Grafton-Cardwell et al. 1999).

Diversity and wildlife

Although cover crops are normally used to serve one of the above discussed purposes, they often simultaneously improve farm habitat for wildlife. The use of cover crops adds at least one more dimension of plant diversity to a cash crop rotation. Since the cover crop is typically not a crop of value, its management is usually less intensive, providing a window of oft human influence on the farm. This relatively ands-off management, combined with the increased on-farm heterogeneity created by the establishment of cover crops, increases the likelihood that a more complex trophic structure will develop to support a higher level of wildlife diversity (Freemark and Kirk 2001).

In one study, researchers compared arthropod and songbird species composition and field use between conventionally and cover cropped cotton fields in the Southern United States. The cover cropped cotton fields were planted to clover, which was left to grow in between cotton rows throughout the early cotton growing season (stripcover cropping). During the migration and breeding season, they found that songbird densities were 720 times higher in the cotton fields with integrated clover cover crop than in the conventional cotton fields. Arthropod abundance and biomass was also higher in the clover cover cropped fields throughout much of the songbird breeding season, which was attributed to an increased supply of flower nectar from the clover. The clover cover crop enhanced songbird habitat by providing cover and nesting sites, and an increased food source from higher arthropod populations (Cederbaum et al. 2004).

See also

Agroecology

Allelopathy

Biological control

Green manure

Nitrogen cycle

Nitrogen fixation

Organic matter

Soil contamination

Further reading

Midwest Cover Crops Council. Resources for growers, researchers, and educators.

Hartwig, N. L., and H. U. Ammon. 2002. 50th Anniversary – Invited article – Cover crops and living mulches. Weed Science 50:688-699.

Sullivan, P. 2003. Overview of cover crops and green manures. ATTRA, Fayetteville, AR.

University of California Sustainable Agriculture Research and Education Program. UCSAREP cover crop resource page.

References

Blackshaw, R. E., J. R. Moyer, R. C. Doram, and A. L. Boswell. 2001. Yellow sweetclover, green manure, and its residues effectively suppress weeds during fallow. Weed Science 49:406-413.

Bohlool, B. B., J. K. Ladha, D. P. Garrity, and T. George. 1992. Biological nitrogen fixation for sustainable agriculture: A perspective. Plant and Soil (Historical Archive) 141:1-11.

Bugg, R. L., and C. Waddington. 1994. Using Cover Crops to Manage Arthropod Pests of Orchards – a Review. Agriculture Ecosystems & Environment 50:11-28.

Cederbaum, S. B., J. P. Carroll, and R. J. Cooper. 2004. Effects of alternative cotton agriculture on avian and arthropod populations. Conservation Biology 18:1272-1282.

CENR. 2000. Integrated Assessment of Hypoxia in the Northern Gulf of Mexico. National Science and Technology Council Committee on Environment and Natural Resources, Washington, DC.

Creamer, N. G., M. A. Bennett, B. R. Stinner, J. Cardina, and E. E. Regnier. 1996. Mechanisms of weed suppression in cover crop-based production systems. HortScience 31:410-413.

Dabney, S. M., J. A. Delgado, and D. W. Reeves. 2001. Using winter cover crops to improve soil quality and water quality. Communications in Soil Science and Plant Analysis 32:1221-1250.

Ditsch, D. C., and M. M. Alley. 1991. Nonleguminous Cover Crop Management for Residual N Recovery and Subsequent Crop Yields. Journal of Fertilizer Issues 8:6-13.

Everts, K. L. 2002. Reduced fungicide applications and host resistance for managing three diseases in pumpkin grown on a no-till cover crop. Plant dis 86:1134-1141.

Freemark, K. E., and D. A. Kirk. 2001. Birds on organic and conventional farms in Ontario: partitioning effects of habitat and practices on species composition and abundance. Biological Conservation 101:337-350.

Galloway, J. N., W. H. Schlesinger, H. Levy, A. Michaels, and J. L. Schnoor. 1995. Nitrogen-Fixation – Anthropogenic Enhancement-Environmental Response. Global Biogeochemical Cycles 9:235-252.

Giller, K. E., and G. Cadisch. 1995. Future benefits from biological nitrogen fixation: An ecological approach to agriculture. Plant and Soil (Historical Archive) 174:255-277.

Grafton-Cardwell, E. E., Y. L. Ouyang, and R. L. Bugg. 1999. Leguminous cover crops to enhance population development of Euseius tularensis (Acari : Phytoseiidae) in citrus. Biological Control 16:73-80.

Haramoto, E. R., and E. R. Gallandt. 2004. Brassica cover cropping for weed management: A review. Renewable Agriculture and Food Systems 19:187-198.

Jensen, E. S., and H. Hauggaard-Nielsen. 2003. How can increased use of biological N-2 fixation in agriculture benefit the environment? Plant and Soil 252:177-186.

Joyce, B. A., W. W. Wallender, J. P. Mitchell, L. M. Huyck, S. R. Temple, P. N. Brostrom, and T. C. Hsiao. 2002. Infiltration and soil water storage under winter cover cropping in California’s Sacramento Valley. Transactions of the Asae 45:315-326.

Kobayashi, Y., M. Ito, and K. Suwanarak. 2003. Evaluation of smothering effect of four legume covers on Pennisetum polystachion ssp. setosum (Swartz) Brunken. Weed Biology and Management 3:222-227.

Kuepper, G., and R. Thomas. 2002. “Bug vacuums” for organic crop protection. ATTRA, Fayetteville, AR.

Kuo, S., U. M. Sainju, and E. J. Jellum. 1997. Winter cover crop effects on soil organic carbon and carbohydrate in soil. Soil Science Society of America Journal 61:145-152.

Lal, R. 2003. Offsetting global CO2 emissions by restoration of degraded soils and intensification of world agriculture and forestry. Land Degradation & Development 14:309-322.

Lazzeri, L., and L. M. Manici. 2001. Allelopathic effect of glucosinolate-containing plant green manure on Pythium sp and total fungal population in soil. Hortscience 36:1283-1289.

Lu, Y. C., K. B. Watkins, J. R. Teasdale, and A. A. Abdul-Baki. 2000. Cover crops in sustainable food production. Food Reviews International 16:121-157.

Morgan, M. F., H. G. M. Jacobson, and S. B. LeCompte. 1942. Drainage water losses from a sandy soil as affected by cropping and cover crops : Windsor lysimeter series c. Connecticut Agricultural Experiment Station, 1942. p. -759 : ill., [New Haven].

Nagabhushana, G. G., A. D. Worsham, and J. P. Yenish. 2001. Allelopathic cover crops to reduce herbicide use in sustainable agricultural systems. Allelopathy Journal 8:133-146.

New Farm, The. Plans for no-till cover crop roller free for the downloading.

Patrick, W. H., C. B. Haddon, and J. A. Hendrix. 1957. The effects of longtime use of winter cover crops on certain physical properties of commerce loam. Soil Science Society of America 21:366-368.

Peoples, M. B., and E. T. Craswell. 1992. Biological nitrogen fixation: Investments, expectations and actual contributions to agriculture. Plant and Soil (Historical Archive) 141:13-39.

Potter, M. J., K. Davies, and A. J. Rathjen. 1998. Suppressive impact of glucosinolates in Brassica vegetative tissues on root lesion nematode Pratylenchus neglectus. Journal of Chemical Ecology 24:67-80.

Rabalais, N. N., R. E. Turner, and W. J. Wiseman. 2002. Gulf of Mexico hypoxia, aka “The dead zone”. Annual Review of Ecology and Systematics 33:235-263.

Romkens, M. J. M., S. N. Prasad, and F. D. Whisler. 1990. Surface sealing and infiltration. Pages 127-172 in M. G. Anderson and T. P. Butt, editors. Process studies in hillslope hydrology. John Wiley and Sons, Ltd.

Sainju, U. M., B. P. Singh, and W. F. Whitehead. 2002. Long-term effects of tillage, cover crops, and nitrogen fertilization on organic carbon and nitrogen concentrations in sandy loam soils in Georgia, USA. Soil & Tillage Research 63:167-179.

Shelton, A. M., and E. Badenes-Perez. 2006. Concepts and applications of trap cropping in pest management. Annual Review of Entomology 51:285-308.

Singh, H. P., D. R. Batish, and R. K. Kohli. 2003. Allelopathic interactions and allelochemicals: New possibilities for sustainable weed management. Critical Reviews in Plant Sciences 22:239-311.

Snapp, S. S., S. M. Swinton, R. Labarta, D. Mutch, J. R. Black, R. Leep, J. Nyiraneza, and K. O’Neil. 2005. Evaluating cover crops for benefits, costs and performance within cropping system niches. Agron. J. 97:1-11.

Teasdale, J. R. 1993. Interaction of light, soil moisture, and temperature with weed suppression by hairy vetch residue. Weed sci 41:46-51.

Thiessen-Martens, J. R., M. H. Entz, and J. W. Hoeppner. 2005. Legume cover crops with winter cereals in southern Manitoba: Fertilizer replacement values for oat. Canadian Journal of Plant Science 85:645-648.

Thomsen, I. K., and B. T. Christensen. 1999. Nitrogen conserving potential of successive ryegrass catch crops in continuous spring barley. Soil Use and Management 15:195-200.

Thorup-Kristensen, K., J. Magid, and L. S. Jensen. 2003. Catch crops and green manures as biological tools in nitrogen management in temperate zones. Pages 227-302 in Advances in Agronomy, Vol 79. ACADEMIC PRESS INC, San Diego.

Tomlin, A. D., M. J. Shipitalo, W. M. Edwards, and R. Protz. 1995. Earthworms and their influence on soil structure and infiltration. Pages 159-183 in P. F. Hendrix, editor. Earthworm Ecology and Biogeography in North America. Lewis Pub., Boca Raton, FL.

Vanlauwe, B., O. C. Nwoke, J. Diels, N. Sanginga, R. J. Carsky, J. Deckers, and R. Merckx. 2000. Utilization of rock phosphate by crops on a representative toposequence in the Northern Guinea savanna zone of Nigeria: response by Mucuna pruriens, Lablab purpureus and maize. Soil Biology & Biochemistry 32:2063-2077.

Vargas-Ayala, R., R. Rodriguez-Kabana, G. Morgan-Jones, J. A. McInroy, and J. W. Kloepper. 2000. Shifts in soil microflora induced by velvetbean (Mucuna deeringiana) in cropping systems to control root-knot nematodes. Biological Control 17:11-22.

Zalom, F. G., P. A. Phillips, N. C. Toscano, and S. Udayagiri. 2001. UC Pest Management Guidelines: Strawberry: Lygus Bug. University of California Department of Agriculture and Natural Resources, Berkeley, CA.

Categories: Crops | Agricultural soil science

About the Author

I am Frbiz Site writer, reports some information about polaris 360 pool cleaner , pcb cleaner.

Pcb Terminal Videos

PCB terminal blocks save time and money – Phoenix Contact

We hope the information that we provided on Pcb Terminal was what you were looking for!

Comments are closed.