Soil Quality Assessment Strategies for Evaluating Soil Degradation in Northern Ethiopia

Table 2

Description of the eight land use and soil management systems (LUSMS) evaluated within the Mai-Negus catchment in northern Ethiopia.

Serial; number	Land use and soil management systems	Description
1	Natural forest (LS1)	Less disturbed land, used as a reference in the system, which has native trees, vegetation, and grass cover.
2	Plantation of protected area (LS2)	Sesbania (Sesbania sesban) and Leucaena (Leucaena leucocephala) trees plantation was established 16 years ago and grass was used by cuting and carrying during the dry season for livestock, protected throughout the year from livestock interferences; no fertilizer application and less intensive soil conservation measures exist.
3	Grazed land (LS3)	Open grazed land appeared during the dry season 16 years ago with no inclusion of any improved management practices, for example, soil and water conservation and enrichment of plant/grass species. It overstocked in the dry months (November–June) but it is a swampy area for the rest of months.
4	Teff (Eragrostis tef)-faba bean (Vicia faba) rotation (LS4)	Fields were harvested of teff (Eragrostic tef (Zucc) Trot) crop before soil samples were collected and rotated with faba bean (Vicia faba  L.) for more than 5-6 years. Urea and diammonium phosphate (DAP) fertilizers were applied each for teff at 50 kg ha^−1 y^−1 but sometimes reduced by half depending on resource availability and quality of the soil. Teff needed 4–6 times tillage and at least one time weeding. For faba bean, 2-3 times tillage was sufficient with no or one time weeding and addition of manure around homestead is common practice but is urea or DAP rarely used. Soil and water conservation was used at field borders.
5	Teff-wheat (Triticum vulgare)/Barley (Hordeum vulgare) rotation (LS5)	The fields were planted wheat (Tritium vulgare L.) before teff (Eragrostic  tef (Zucc) Trot) and soil samples were collected after teff was harvested. Wheat (Triticum vulgare L.)/barley (Hordeum vulgare  L.) with teff (Eragrostic tef) was rotated for more than 6 years. 50 kg ha^−1 y^−1 of each urea and DAP fertilizers was used for teff field but the amount varies with crop color at vegetative stage and soil quality condition for fertilizer rate application on wheat/barley crop fields. The fertilizer rate used for wheat/barley is lower than teff.
6	^aTeff mono-cropping land system (LS6)	For more than 5-6 years, teff (Eragrostic tef (Zucc) Trot) was sown continuously with 50 kg ha^−1 y^−1 urea and 100 kg ha^−1 y^−1 DAP fertilizers; 5–7 tillage frequency; at least one time hand weeding. Manure and intensive SWC for fields around homestead was applied.
7	Maize (Zea mays L.)-mono cropping land system (LS7)	Maize (Zea mays L.) was planted for more than 20–30 years continuously. The addition of manure was estimated at 6–12 t ha^−1 y^−1, which varies with manure and labor availability for transportation; 2-3 tillage frequency with at least one times hand hoeing and weeding. This is always practiced around homestead fields. Conservation measures are also well executed.
8	Uncultivated marginal land system (LS8)	It was terraced with wide spacing since the last 20 years but most of it is broken and used as an open grazing land throughout the year; on some spot areas it had very few to few naturally growing but over grazed grass species like Bermuda grass (Cynodon dactylon L.) management practices such as fertilizer and species enrichment were not introduced. Farmers considered it as the most degraded soil, for example, abandoned land.

aTeff is the dominant crop in the study catchment and other parts of northern Ethiopia. It is an annual cereal crop (belonging to the grass family) which has sparse crop canopies and provides little cover to the soil against erosion. It has very fine seeds that require repeated plowing of fields and preparation of fine seedbeds, which increases the vulnerability of the soil to erosion.