THE POSSIBILITY OF MEASURING AGRICULTURAL PRESSURE ON SOIL MAPPING UNITS

Many soil mapping units (MU) have not been adequately sampled to provide a true measure of their variability; therefore, their descriptions must be regarded as incomplete, and valid statistical comparisons cannot be made with other closely related MU. The number of samples required to detect the differences in means of 18 soil properties between Brantford and Beverly Silt Loam MU were calculated and they ranged from 4 at the 80% probability level (10 at the 95% probability level) for organic matter content of the Ap horizon to several thousand for pH of the Ap horizon. Calculation of required sample numbers indicated that sufficient samples had been collected to make valid statistical comparisons between seven of the soil properties. All seven properties were found to be significantly different between the two MU at the 95% probability level. However, only two of the properties, hue and organic matter content of the Ap horizon, had distinctly different modal values between the two MU and neither of these properties is easily measured in the field. Therefore, it was concluded that the 18 soil properties examined were impractical and unreliable criteria for separating the MU in the field. But, the MU separations can be readily and validly made on the basis of landscape position.

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Soil-landscape Relationships in the Occidental Plateau of São Paulo State, Brazil: I. Geomorphic Surfaces and Soil Mapping Units

Soil Science Society of America Journal ◽

10.2136/sssaj1977.03615995004100010030x ◽

1977 ◽

Vol 41 (1) ◽

pp. 104-109 ◽

Cited By ~ 29

Author(s):

I. F. Lepsch ◽

S. W. Buol ◽

R. B. Daniels

Keyword(s):

Sao Paulo ◽

Soil Mapping ◽

São Paulo ◽

Paulo State ◽

Soil Landscape ◽

São Paulo State ◽

Geomorphic Surfaces ◽

Mapping Units

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Toward delineating hydro-functional soil mapping units using the pedostructure concept: A case study

Computers and Electronics in Agriculture ◽

10.1016/j.compag.2012.04.011 ◽

2012 ◽

Vol 86 ◽

pp. 15-25 ◽

Cited By ~ 5

Author(s):

Mohammed Salahat ◽

Rabi H. Mohtar ◽

Erik Braudeau ◽

Darrell G. Schulze ◽

Amjad Assi

Keyword(s):

Soil Mapping ◽

Mapping Units

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The Soil Survey and Its Value in the Ad Valorem Taxation of Privately Owned Timberland

Southern Journal of Applied Forestry ◽

10.1093/sjaf/7.4.204 ◽

1983 ◽

Vol 7 (4) ◽

pp. 204-208

Author(s):

R. Bruce Harding ◽

Robert D. Baker

Keyword(s):

Loblolly Pine ◽

Site Index ◽

Soil Mapping ◽

Soil Survey ◽

Significant Difference ◽

Suitable Site ◽

Soil Surveys ◽

Privately Owned ◽

Mapping Units

Abstract The use of detailed county soil surveys for predicting site productivity was evaluated for taxation purposes. One hundred and thirty permanent forest inventory plots containing suitable site index trees for loblolly pine (Pinus teada L.) were located on 11 different soil mapping units in the Sam Houston National Forest in Texas. The correlation between the field site indices for the mapping units and the site indexes projected by the Soil Conservation Service (SCS) was extremely low (r = .10). Analysis of variance for the soil mapping units suggested that the actual average site index between mapping units was significantly different. Duncan's multiple range test, however, showed that these differences were limited to those soils having extreme site index values, with the majority of the mapping units showing no significant difference in productivity. Detailed county soil surveys provided an inadequate basis for determination of productivity as defined by site index for taxation purposes.

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Taxonomy and Soil Mapping Units: A Reply to R. L. Guthrie

Soil Horizons ◽

10.2136/sh1983.1.0016 ◽

1983 ◽

Vol 24 (1) ◽

pp. 16

Author(s):

John Doe

Keyword(s):

Soil Mapping ◽

Mapping Units

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Soil Fertility Status in Relation to Farmers’ Practices Under Maize Based Systems in Western Region of Kenya: Yield Gap Analysis

Journal of Experimental Agriculture International ◽

10.9734/jeai/2019/v33i630161 ◽

2019 ◽

pp. 1-12

Author(s):

E. M. Muya ◽

J. M. Miriti ◽

M. Radiro ◽

A. Esilaba ◽

A. L. Chek ◽

...

Keyword(s):

Soil Fertility ◽

Soil Mapping ◽

Productivity Index ◽

Soil Productivity ◽

Western Region ◽

Yield Gap ◽

Fertility Status ◽

Yield Gaps ◽

Soil Fertility Status ◽

Mapping Units

A study was carried out in Kenya Cereal Enhancement Project site in Western region of Kenya to examine the soil fertility status in relation to the current blanket fertilizer recommendations and farmers’ practices across the four wards, namely: Motosiet, Keiyo, Cherangani and Kwanza. The baseline fertility status in different soil mapping units was assessed in terms of soil productivity index with a view of analyzing the levels of nutrients and yield gaps. Using the standard soil survey procedures, six soil mapping units were identified as UUr1, UUr2, UUr3, RUd, RUrb, and BU1.. The results showed that the highest productivity index was in unit BU1, followed by UUr1, UUr2, UUr3, and RUrb with values of 40.5, 29.4, 25.0, 16.0 and 8.9% respectively. Keiyo Ward had the highest level of nitrogen, being 125.82, followed by Motosiet, Cherangani and Kwanza with values of 99.92, 97.12, and 81.12 kg/ha respectively. Phosphorous level was highest in Kwanza (136.41 kg/ha), followed by Cherangani (106.82 kg/ha) and Keiyo Ward (76.08 kg/ha). The lowest level was recorded in Motosiet with the value of 72.56 kg/ha. Potassium was found to be adequate in all the four Wards with values ranging between 347.67 and 410.34 kg/ha. The maximum maize production recorded in the project sites was 9,000 kg/ha, with a yield gap of 1,000 kg/ha. This was achieved through application of 100 and 50 kg/ha of DAP and CAN respectively. This was followed by 6,750 kg/ha obtained through application of 50 kg/ha of DAP and CAN. The yields from the rest of the sites ranged between 1,800 and 4,500 kg/ha with yield gaps varying from 3,250 to 8,650 kg/ha. The lowest yields were obtained in Keiyo, followed by Kwanza Ward despite the relatively high macro- nutrient levels in the soils of the two Wards. This was attributed to soil-related constraints caused by the increased soil structural degradation and loss of soil tilth. Therefore, it is recommended that the envisaged climate smart technologies be geared towards enhancement of nutrient and water use efficiency through improved soil structure and tilth.

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