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Application Problem #3
Jessica Ruggieri
Please read and follow the rules provided in the Assignment Instructions
1. A young farmer has hired Silt, Sand and Beyond, LLC for irrigation advise. Emily
grows hops – a high-value specialty crop – in her farm in western Massachusetts.
Her farm has two fields, for which you’ve collected the data in Table 1. You also
have found Fig. 1 on the interwebs: soil moisture characteristic curves for a few
different soil textures.
Table 1. Particle size distribution, wet weight and oven-dry
weight of soil samples from the North and East field.
Sample volume was 200 cm3.
Sampling Particle size Wet weight Oven-dry
location distribution (%) (g) weight (g)
Sand Clay
North field 30 30 320 300
East field 85 5 300 250
Fig. 1. Soil moisture characteristic curves for
a few different soil textures.
It’s the middle of the summer and it has not rained for a couple of weeks. Emily
wants to know whether she needs to irrigate – she’s worried her crops may be
wilting soon if she does nothing.
Determine the textural class of each soil
o The texture of the North field is clay loam. The texture is sand.
Calculate the bulk density for each soil
o North Field: 300g/200cm3=1.5g/cm3
o East Field: 250g/200cm3=1.25g/cm3
Calculate the mass (gravimetric) water content for each soil
o North Field: (320g-300g)/300g=20g/300g=0.066g/g
o East Field: (300g-250g)/250g=50g/250g=0.020 g/g
Calculate the volumetric water content for each soil