Loams cropping

Figure 8 The effect of fertilizer application and rainfall and the emissions of NO and N,0 from clay loam soils cropped with ryegrass cut for silage in South Scotland.

For studies involving test substance application to soil, there may be a requirement for more soil information than for studies where applications are made to foliage of established crops. The study protocol should describe any specific requirements relative to soil type selection and how to confirm the soil characteristics for the study. Most studies simply require that the soil be identified by its name (e.g., Keystone silt loam) and composition (e.g., percent sand, silt, and clay). This information can typically be acquired from farm records, a soil survey of the local area, or a typical soil analysis by a local soil analysis laboratory. In some instances, a GLP compliant soil analysis must be completed. The study protocol must clearly define what is needed and how it is to be obtained. Unless specified in the protocol, non-GLP sources are adequate to identify the soil and its characteristics. The source of the soil information should be identified in the field trial record. 

Study 1. Wheat ( McNair 1813 ) was planted at the Central Crops Research Station near Clayton (Lynchburg sandy loam) and the Tidewater Research Station near Plymouth (Bayboro loam), North Carolina, at a rate of 101 kg/ha in October of 1980. The following spring or early summer, plots were set up in which a green wheat cover crop or wheat straw and stubble remaining after wheat harvest was (1) left... 

Rogers CW, Brye KR, Smartt AD, Norman RJ, Gbur EE, Evans-White MA. Cultivar and previous crop effects on methane emissions from drill-seeded, delayed-flood rice production on a silt-loam soil. Soil Sci. 2014 179 28-36. 

Nwosu JU, Harding AK, Linder G. 1995. Cadmium and lead uptake by edible crops grown in a silt loam soil. Bull Environ Contam Toxicol 54 570-578. 

Haraldsen TK, Asdal A, Grasdalen C, Nesheim L, Ugland TN (2000) Nutrient balances and yields during conversion from conventional to organic cropping systems on silt loam and clay soils in Norway. Biol Agric Hort 17 229-246... 

Nishita, H., Steen, A.J., and Larson, K.H., 1958, Release of strontium-90 and cesium-137 from vina loam upon prolonged cropping. Soil Sci. 86 195-201. 

Munkholm, L.J., Schjonning, P. and Petersen, C.T. 2001a. Soil mechanical behaviour of sandy loams in a temperate climate case studies on long-term effects of fertilization and crop rotation. Soil Use and Management 17 269-277. 

Bayer, C., Martin-Neto, L., Mielniczuk, J., and Ceretta, C. A. (2000). Effect of no-till cropping systems on soil organic matter in a sandy clay loam Acrisol from Southern Brazil monitored by electron spin resonance and nuclear magnetic resonance. Soil Til. Res. 53, 95-104. 

Simazine was the main product studied in early research on the triazines for weed control in tree fruits and vineyards (Doll, 1960 Larson and Ries, 1960). On mature grapevines in a deep, fine, and sandy loam soil, no differences in crop tolerance were observed between simazine and atrazine (Leonard and Lider, 1961). However, subsequent studies indicated that grapevines were more tolerant to simazine than to atrazine (Lange et al., 1969a). Prometryn was intermediate between the two in terms of crop tolerance (Lange et al., 1969a). 

Bharati, L. (1997). Infiltration in a Coland clay loam under a six-year old multi-species riparian buffer strip, cultivated row crops and continually grazed pasture. M.S. Dissertation, Iowa State University, Ames, IA. 

Sandy loam SL 15-25 mm Coherence slight Sandy to touch. Clay is 10-20% Root growth of annuals and perennials is not restricted but has a high susceptibility to mechanical compaction. Very slight restriction on water movement soil water is available to most crops and trees. Water drains from the soil readily but not rapidly. 

Cassava is a shrubby perennial crop which is well-recognized for the ease of plantation and low input requirement. The plant can grow in all soil types, but root formation is better in loose-structured soils, such as light sandy loams and/or loamy... 

Lichtenstein and Schultz (7) found that the persistence of aldrin in soil depended largely on the presence of water in the soil. They concluded that once aldrin had been displaced by water from the soil particles, a major part of the insecticide was lost by volatilization. Unlike aldrin, DDT did not respond to displacement by water nor was it affected by enlargement of the surface onto which it had been deposited. Under field conditions, daily disking of a treated loam soil reduced 38% of the aldrin residue and 25% of the DDT residue after 3 months. In another study, Lichtenstein et al. (6) were able to recover aldrin and heptachlor residues ranging from 2.7 to 5.3% of the applied dosage 4 months after application to the soil surface. The persistence increased by a factor of 10 when the insecticides were mixed with the soil by rotatilling. One year after application 90% of the recovered insecticides was found in the upper 3 inches of the soil. Because two to three times more insecticide residues were recovered from crop-covered plots than from fallow ones, it was concluded that a dense... 

The plot soil, of loessial origin, is a coarse silt loam belonging to the Shano series. The top soil, very fine and powdery, is high in inorganic nutrients and low in organic matter. The plot was irrigated down a 1.88% slope, having been cropped for only 3 years. 

The ranges of solid-liquid distribution coefficients reported for Co in different soil types are rather similar. In general, Kd values from 0.2 to 20,000 L kg l are representative of sand, loam, clay, and organic soils. Sheppard and Thibault (1990) quote median Kd values of 60, 1300, 540, and 990 L kg for each of these soil types, respectively. Soil—plant transfer factors for numerous crop species have been published by the International Union of Radioecologists (lUR, 1989). These values range from 0.037 for cereal grain to 1.1 for alfalfa fodder. For most of the crop types represented in the lUR (1989) database, a range of soil-plant transfer factors from 0.01 to 0.1 seems most applicable. 

Table IV sunmarlzes the water balance results of all the calibration scenarios. A trend that can be seen from this data is that evapo-transpiration demand in Wisconsin is consistently around 43 cm for the summer months between May and September, regardless of irrigation added or soil type. Recharge was higher for the loamy sand soil in Hancock, 35 cm, than for the sandy loam in Cameron, 26 cm. Recharge increased to 53 cm when 19 cm of extra irrigation water was added to the sand soil, indicating that this extra irrigation was not needed by the crop. Evapo transpiration in North Carolina...

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