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