Crop sequence

Arable farmers in the UK rarely grow more than one crop in a year, but horticulturalists may grow two or more crops in a year on the same soil, so the question of crop sequences is more intense for them, particularly as Brassica vegetables, such as cabbages and brussel sprouts, can leave large organic as well as mineral nitrogen residues. 

Young, L.D. (1994) Changes in the Heterodera glycines female index as affected by ten year cropping sequences. Journal of Nematology 26, 505-510. 

Hansen B, Alroe HF, Kristensen ES (2001) Approaches to assess the environmental impact of organic farming with particular regard to Denmark. Agric Ecosyst Environ 83 11-26 Harinikumar KM, Bagyaraj DJ (1989) Effect of cropping sequence, fertilizers and farmyard manure on vesicular-arbuscular mycorrhizal fungi in different crops over three consecutive seasons. Biol Fertil Soils 7 173-175... 

Leake, A.R. 1996. The effect of cropping sequences and rotational management an economic comparison of conventional, integrated and organic systems. Aspects of Applied Biology 47 185-195. 

Franzluebbers, A.J., Francis, C.A. and Walters, D.T. 1994. Nitrogen fertilizer response potential of corn and sorghum in continuous and rotated crop sequences. Journal of Production Agriculture 7 193-194. 

These include management of crop sequences, utilization of allelopathic crop residues, breeding crops for weed control, and development of allelochemicals as herbicides. 

Chemical analysis of sweetgum seedlings treated with fescue leachates showed that growth inhibition was associated with an impaired absorption of phosphorus an nitrogen. Obviously, conditions of decomposition, allelochemical enhancement of disease, the nature of the secondary products from microbial activity, and interactions among allelochemicals are all significant variables in intercrop allelopathy. The uniqueness of the chemical environment for each crop sequence and situation will continue to confound precise analyses of effects on yield. 

Possibly picking the right crop sequence can result in yield stimulation, as suggested for corn following soybeans. While the list of observations on inhibitory and stimulatory effects can be extended, little documented evidence on causative factors or the actual impact on productivity is available,... 

Eghball, B., L.N. Mielke, G.A. Calvo, and W.W. Wielhelm. 1993a. Fractal description of soil fragmentation for various tillage methods and crop sequences. Soil Sci. Soc. Am. J. 57 1337-1341. 

Chen SY, Reese CD. Parasitism of the nematode Heterodera glycines by the fungus Hirsutella rhossiliensis as influenced by crop sequence. J Nematol 31 437-444, 1999. 

The net return (NR) was calculated as gross income from the crops produced minus the direet produetion costs for each management strategy, cropping sequence, and year. NR was expressed as the return per one hectare averaged over either 2 or 4 crops. The... 

Using the assigned distributions of crop yields and crop market prices, CB calculated 500 different possible random draw combinations of crop yields and prices. Using these 500 possible outcomes of yield and price, in addition to input costs, and potential organic premiums, 500 possible outcomes of NR for each input strategy and cropping sequence... 

Table 4. PriceATield correlations for each crop in each cropping sequence and...

First-degree stochastic dominance (FSD) and seeond-degree stochastic dominance (SSD) were used to determine farmers potential risk preferences between input strategies and cropping sequences (Hardaker et ai, 1997). 

Figure 1. Com yield by cropping sequence and management strategy, 1990-1999...

Figure 2. Soybean yield by cropping sequence and management strategy, 1990-1999 Table 6. Average crop yields for each crop in each cropping sequence and management...

Table 8. Average net returns for eaeh erop in each cropping sequence and management strategy from 1990 through 1999 in the VICMS II study (USD/hectare) ...

The practical on-farm management of soil, the setting of targets and the monitoring of target achievement and the decisions taken about what crops to grow and when they should appear in the cropping sequence are fundamental to successfid crop... 

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