Multicote Agri allows the reduction of N application rate in macadamia nut

Although N application rate was reduced by 25%, Kernel yield was 33% higher than the control practice

Crop/cultivar

Macadamia Nut /344
Country / location / date Australia; Northern N.S.W. / Alstonville, clayish soil, rain-fed / 2005
Objectives Comparison of the Mgro concept at different N;P;K ratios and application rates, with current fertilization practice of an established plantation
Haifa product tested Multicote Agri 21-13-20 (8M) (50-0-50% coated)
Multicote Agri 16-5-30 (8M) (50-0-50% coated)
Application method Side dressing
Tested treatment

Control:
Four bi-monthly side-dressing applications of 150 kg/ha of 15-10-14, each; in Sept. Nov., Jan. & March, supplying a total of 90-60-83 kg/ha of N-P2O5-K2O, respectively

Multicote Agri. 
One side dressing application in September
160 kg/ha, (40% of the control N), of 21-13-20 (8M)
or 240 kg/ha, (60% of the control N) of 21-13-20 (8M)
or 320 kg/ha, (80% of the control N) of 21-13-20 (8M)
or 315 kg/ha, (60% of the control N) of 16-5-30 (8M)

 Treatments results

 Observation at harvest of 1st year

 

Gross yield (kg/ha)

Kernel recovery (%)

Kernel yield (kg/ha)

Control

6,886 a

36.7 a

2,527 a

160 kg/ha, of 21-13-20

6,830 a

36.4 a

2,486 a

240 kg/ha, of 21-13-20

8,025 b

36.8 a

2,953 b

320 kg/ha, of 21-13-20

9,140 c

36.9 a

3,372 c

315 kg/ha, of 16-5-30

6,980 a

37.1 a

2,590 a

Conclusion These results clearly demonstrate the superiority of the application of 320 kg/ha, of 21-13-20. This treatment applied 25% less N, and yet produced highest kernel yield, which was 33.4% higher than the control practice, and resulting in a $US/ha 2,160 above the control. Additional fertilizer and application costs of this treatment amounted to $US 48.- only.
Kernel recovery rate (% nut vs. shell, w/w) must be over 33%, which was obtained in all treatments, but the 320 kg/ha, of 21-13-20 treatment scored best also for this parameter, but the difference is not significant.
This experiment is run over the next two seasons
Reference Matt Thomas – Multifert Agencies, Victoria, Australia