12 Dec 2013

The Longerenong Wrap

3 years of cropping - what happened?
Wheat on the stalk


The Longerenong Cropping challenge gives local advisors the opportunity to put their agronomic skills on show by managing a crop within a three year cycle of canola, wheat and then chickpeas. The plots were all replicated and outcomes assessed annually on the basis of yield, quality and returns. Twelve groups participated in the challenge and while seasonal conditions - as always - varied from year to year, the average financial return for the challenge was $857/ha. The financial returns were highest in the canola and lowest in the wheat crops, which largely reflected the seasonal conditions for each. The highest gross margin was achieved by a group of current students at Longerenong College with a return of $959/ha per year over the three years.

A cropping system experiment such as this also allows some estimates to be made of nutrient use. Phosphorus rates used by the groups varied from 7 kg P/ha/y to 13 kg P/ha/y. There was a weak relationship between P application rate and return. The partial factor productivity for P averages 306 (+/- 56) kg grain/kg P combined over the three crops in the rotation, even though the Colwell P status of the site was considered moderate to high depending on crop. The partial nutrient balance for P over the three years (amount of P removed in grain divided by the amount of fertilizer P added) was nearly always positive, and averaged 1.2 kg P removed for each kg P applied.

Table 1 shows the results by group for financial return as well as the P balance data and P use efficiencies as measured by partial factor productivity (PFP) and partial nutrient balance (PNB) for the groups over the three years of the challenge.

Group
Means P rates
P Balance kg P/ha
PNB kg grain/kg P
PFP kg Grain P/kg Fertilizer P
Gross Margin $/ha
Agritech
13
-2
0.94
234
845
BCG
8
6
1.22
313
759
DPI
10
6
1.20
313
923
IPL 9P20N
13
-1
0.96
244
803
Green Machine
13
3
1.08
283
915
Longy Lecturers
9
6
1.22
342
794
Longy Students
10
9
1.29
306
959
Pacific Seeds
11
3
1.10
280
901
Raging Reds
11
8
1.24
317
892
SMS Rural
9
9
1.31
326
883
Tylers /Agwise
12
0
0.99
264
781
VTNFA
7
15
1.70
448
825

More about: Longerenong Cropping Challenge