26.03.2013 Views

Desire for Greener Land

Desire for Greener Land

Desire for Greener Land

SHOW MORE
SHOW LESS

You also want an ePaper? Increase the reach of your titles

YUMPU automatically turns print PDFs into web optimized ePapers that Google loves.

Classification<br />

<strong>Land</strong> use problems: There is a lack of water <strong>for</strong> irrigation of crops limiting the crop types that can be planted as well as the crop yield of<br />

dryland farming. A lack of water availability seriously limits the production potential of the soil and results in a low vegetation/crop cover.<br />

The relatively high soil erosion rates cause various off-site related problems (i.e. flooding, reservoir siltation) and on-site problems (i.e.<br />

gully <strong>for</strong>mation and loss of soil depth).<br />

<strong>Land</strong> use Climate Degradation Conservation measure<br />

tree and shrub<br />

cropping<br />

(rainfed)<br />

Soil depth (cm)<br />

0-20<br />

20-50<br />

50-80<br />

80-120<br />

>120<br />

agro<strong>for</strong>estry semi-arid,<br />

subtropics<br />

Stage of intervention Origin<br />

Prevention<br />

Mitigation / Reduction<br />

Rehabilitation<br />

Main causes of land degradation:<br />

Direct causes - natural: droughts<br />

Main technical functions:<br />

- water harvesting / increase water supply<br />

- control of concentrated runoff: retain / trap<br />

- control of concentrated runoff: impede / retard<br />

- control of concentrated runoff: drain / divert<br />

- increase of infiltration<br />

Environment<br />

Natural Environment<br />

Average annual rainfall<br />

(mm)<br />

> 4000<br />

3000-4000<br />

2000-3000<br />

1500-2000<br />

1000-1500<br />

750-1000<br />

500-750<br />

250-500<br />

< 250<br />

water<br />

degradation:<br />

aridification<br />

<strong>Land</strong> user's initiative: > 50 years ago<br />

Experiments / research<br />

Externally introduced:<br />

Growing season(s): 220 days (November until June)<br />

Soil texture: medium (loam)<br />

Soil fertility: low<br />

Topsoil organic matter: medium (1-3%)<br />

Soil drainage/infiltration: poor (eg sealing /crusting)<br />

structural:<br />

bunds and bench<br />

terraces (slope<br />

of terrace bed 4000<br />

3000-4000<br />

2500-3000<br />

2000-2500<br />

1500-2000<br />

1000-1500<br />

500-1000<br />

100-500<br />

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!