The Nutrition of Almonds

Nitrogen
Almonds are among the most efficient crops studied
in terms of nitrogen (N) uptake. The requirement for
N fertiliser application is based on crop demand which
is driven by crop yield. Hence, higher yields require
more N than lower yielding crops. General fertiliser N
applications rates should be 0.1 Kg N / Kg of targeted
nut yield. Rates may need to be increased if trees are
still actively expanding, as additional N will be needed
for permanent tissue or if there are other losses/
inefficiencies. Shortages of N will reduce growth and
yields.
The acidifying effect of nitrogen fertiliser is well
documented. Low soil pH can cause many nutrient
issues, reducing plant growth and crop yields. Supplying
nitrogen as nitrate can reduce soil acidification and lower
the requirement for lime as can been seen in Figure 1.
The lime requirement for individual nitrogen fertiliser is
presented in Table 1.
Table 1: Lime requirement to neutralise acidifying effect of various fertilisers
Product Lime required when N leached (Kg CaCO3 / 100 Kg N)
Yara Liquids N-CAL 15+18Ca/
YaraLiva CALCINIT
0% 50% 100%
-360 -180 0
YaraLiquids N-CAL 28+9Ca -70 100 290
YaraLiquids N-CAL 35+6Ca -50 130 310
YaraLiquids N-CAL 23+12Ca -150 30 210
UAN/ Urea 0 180 360
Ammonium Sulphate 360 540 720
Yara Liquids N25 0 180 360
A negative value indicates a positive liming effect from the addition of fertiliser. Some additional acidification can
occur if basic cations are leached with anions in the soil solution e.g. sulphate.
Source: Moore, G., Dolling, P., Porter, B and Leonard, L. (1998). Soil Acidity. In ‘Soilguide. A handbook for understanding and managing
agricultural soils’. (ed. G. Moore), Agriculture Western Australia Bulletin No. 4343, pp. 127–140.
Figure 1. Impact of N form on soil pH in wet zone under drip irrigation
Yara I 3