Finley irrigated wheat, canola and faba bean systems results 2014

Take home messages

• Deciding how much water to allot for mainstream rice and corn crops, and for irrigated winter crops, is a challenge for farmers in low water allocation seasons.
• It is assumed high yielding wheat, canola and faba bean crops, which need more water, are more profitable per hectare and mega litre than lower yielding crops.
• Many winter crop paddocks are not suited to high yields because of limitations in soil type, layout, rotation, risk and labour availability.
• The Finley Discussion Group's irrigated wheat, canola and faba bean records were analysed as irrigation systems allowing comparison of yield, water use, gross margin/ha and gross margin/ML.
• The wheat 1.5 to 2 ML/ha spring water use system had the highest GM/ML at $406/ML, compared to $268/ML for the higher yield target spray system, and $226/ML for the higher yield target flood >2 ML system.
• Similarly the canola <1 ML/ha spring water use system had the highest GM/ML at $149/ML, compared to $90/ML for the higher yield target spray system, and $118/ML for the higher water use flood =/>1 ML system.
• High yields and prices for faba beans contributed to a spray (only 2 crops) system GM/ML of $407, with a GM/ML of $401 for the four flood system crops.

Background

Each irrigation season farmers make decisions on what do with their water. The decision is generally made between winter grain and grazing crop, and mainstream rice and corn crops. In lower allocation years like this one, the water market becomes important as farmers decided whether it is profitable buying water for extra winter crop watering and for maintaining rice and corn programs.

There has been much research and extension focussing on high irrigated wheat yields. The 'Growing eight tonnes per hectare of irrigated wheat in southern NSW' Prime Fact 197 (Lacy and Giblin), produced in 2006 and widely used for attaining 8 t/ha yield is an example.

However, the catch with high yielding systems is that more irrigation water is required, and there is more risk. In reality there is not enough water for targeting 8 t/ha of wheat or 4 t/ha of canola in every paddock. There are also soil type, layout, labour availability and rotation limitations.

So what were the winter crop systems farmers used in 2014?

The 2014 cropping systems

The Finley Discussion Group's irrigated wheat and canola crop records are usually classed in order from top to lowest yield, and on water use efficiency (WUE). While the results from this method have been very useful, it was decided to separate and analyse the 2014 records into irrigation systems and include the new crop faba beans.

This paper covers:

• irrigated wheat systems;
• irrigated canola systems; and
• irrigated faba bean systems.

Irrigated wheat systems

Yield and irrigation

Table 1 shows the six irrigated canola systems - spray and the flood systems: spring irrigated water use >2 ML/ha; water use 1.5 to 2 ML/ha (2 spring irrigations); <1.5 ML/ha (1 spring irrigation); pre-irrigation plus spring irrigation; grazing and grain; and no irrigation water use.

Table 1. Irrigated wheat systems results 2014.

System	No. Crops	Target yield (t/ha)	Yield achieved (t/ha)	Total N (kg/ha urea)	Spring irrig (ML/ha)	Extra yield over dryland (t/ha)	Irrigation WUE (t/ha)
Spray	7	7.1	6.2	299	2.1	3	1.4
Flood >2 ML	13	6.7	6.4	246	2.8	3.2	1.1
Flood 1.5-2 ML	8	6.5	6.2	170	1.6	3	1.9
Flood <1.5 ML	12	5.4	4.2	181	1	1	1
Flood pre/spr	12	6.1	4.9	224	2.4	1.7	0.7
Grazing/grain pre/spr	5	5.4	4.3	240	2.4	1.1	0.5
No irrigation	7	4.6	2.9	137	0	0.2	-
Dryland	28	-	3.2	-	-	-	-

There were 20 crops of the high yielding 7-8 tonne target spray irrigation and flood >2 ML/ha systems. The target yields for the spray system of 7.1 t/ha and 6.7 t/ha for the >2 ML system were lower than expected, as were the attained yields of 6.2 t/ha for the spray system and 6.4 t/ha flood system. The highest yields were around 8 t/ha. The spray system with lower water use had a higher irrigation WUE of 1.4 t/ML compared to the flood system of 1.1 t/ML.

There were 44 crops grown in the other systems.

The 1.5-2 ML/ha system used less water than the >2 ML/ha system, but the yield was similar resulting in the highest WUE of any system of 1.9 t/ML. The often used <1.5ML/ha one irrigation system had a lower yield and low WUE of 1t/ML.

Both the pre-irrigation/spring and grazing and grain systems had pre-irrigations which pushed up the water use.

Gross margins

Table 2 shows the systems with gross margin per hectare (GM/ha) and gross margin per mega litre (GM/ML). The 1.5-2 ML system had a very high GM/ML of $406, and grazing and grain system had a GM/ML of $293/ML. In this case, farmer income estimates from sheep grazing was added as extra grain yield. Both were higher than the high yield spray and >2 ML systems which were $268/ML and $226/ML respectively. The <1.5 ML system had the lowest GM/ML of $150.

Table 2. Irrigated wheat system gross margins.

System	Yield (t/ha)	Price ($/ha)	Variable costs per ha	Gross margin per ha	Gross margin per ML
Spray	6.2	282	690	1058	268
Flood >2ML	6.4	273	620	1127	226
Flood 1.5-2 ML	6.2	273	549	1144	406
Flood <1.5 ML	4.2	273	502	645	150
Flood Pre/spr	4.9	273	544	794	124
Flood graze/grain	4.3 (6.8)	259	563	1198	293
No irrigation	2.9	273	357	435	-

* The average dryland wheat gross margin $495/ha was subtracted from the irrigation gross margins ensuring the GM/ML was attributed to the irrigation water applied

** Actual input costs and prices were averaged for each system, but in reality individual farmer yields, variable costs and prices, and hence GM/ML, may vary widely from the averages

*** The gross margins do not include any allowance for purchasing market water

Irrigated canola systems

Yield and irrigation

Table 3 shows the six irrigated canola systems – spray and the flood systems: spring irrigated water use >1ML/ha; water use <1.0ML/ha (1 spring irrigation); pre-irrigation plus spring irrigation; grazing and grain; and no irrigation water use.

There were 16 crops of the high yielding 3-4 tonne spray irrigation and >1 ML/ha systems. The low target yields of 3.1 t/ha for the spray system and 2.5 t/ha for the >1ML system reflect farmer frustration of not being able to grow consistent 3.5 t/ha yields, with the 2 highest yields being 4 t/ha and 3.5 t/ha. This is evident by the spray system yield of 2.9 t/ha and 2.4 t/ha for the >1 ML system. Lower prices and the low water allocation may have also influenced farmers to reduce spring irrigations and yield potential. The higher spray system water use of 2.1 ML/ha and yield compared to 1.1 ML/ha for the >1 ML/ha system seems to indicate another irrigation was needed to match the spray system.

Another comment from farmers was the relatively high dryland yield 1.9 t/ha compared to the irrigated systems yields.

Thirty crops were grown in other systems.

The <1 ML/ha system, using less water than the > 1ML/ha system, had equal yields and a better WUE of 0.6 t/ML. The lowest WUE system was grazing and grain at 0.1 t/ML but there were only 2 crops included in the analysis. As with the wheat gross margin, when lamb grazing income is included, the GM/ML is higher.

Table 3. Irrigated canola systems.

System	No. crops	Target yield (t/ha)	Yield achieved (t/ha)	Total N (kg/ha urea)	Spring irrigation (ML/ha)	Extra yield over dryland (t/ha)	Irrigation WUE (t/ML)
Spray	6	3.1	2.9	310	2.1	1	0.5
Flood =/>1ML	10	2.5	2.4	196	1.1	0.5	0.5
Flood<1/ML	10	2.5	2.4	184	0.8	0.5	0.6
Flood pre/spr	5	2.5	2.3	207	1.5	0.4	0.3
Grazing/grain	2	3	2	223	1.3	0.1	0.1
No irrigation	3	2.8	2.2	192	0	0.3	-
Dryland	20	-	1.9	-	-	-	-

Gross margins

Table 4 shows lower GM/ha and GM/ML compared to wheat. The <1 ML system had the highest GM/ML of $206 and a good GM/ha of $587. The grazing and grain system had the second highest GM/ML of $195. Although the >1 ML system had 0.5 t/ha lower yield than the spray system, the lower irrigation water use led to a higher GM/ML of $160 compared to the spray system of $112/ML. The pre/spr (pre-irrigation/watering up/spring irrigation) system had the lowest GM/ML of $96 as the pre-irrigation was excess to the high rainfall from April to June.

Table 4. Irrigated canola system gross margins.

System	Yield (t)/ha	Price ($/tonne)	Variable costs per ha	Gross margin per ha	Gross margin per ML
Spray	2.9	455	662	658	90
Flood =/>1ML	2.4	464	516	598	118
Flood <1.5ML	2.4	455	505	587	149
Flood Pre/spr irrig	2.3	458	474	579	74
Flood Graze/grain	2 (2.4)	460	474	630	125
No irrigation	2.2	422	466	462	-

*The average dryland canola gross margin $468/ha was subtracted from the irrigation gross margins ensuring the GM/ML was attributed to the irrigation

** Actual input costs and prices were averaged for each system, but in reality individual farmer yields, variable costs and prices, and hence GM/ML, may vary widely from the averages

*** The gross margins do not include any allowance for purchasing market water

Irrigated faba bean systems

Yield and irrigation

Table 5 shows the results for the two irrigated faba bean systems – spray (2 crops) and the flood system (4 crops). The yields for the 2 spray crops were very high at 4.9 t/ha and exceeded the target yield. The flood yield of 4.2 t/ha was also very good. The spray irrigation water use was higher than flood, but maybe affected by lack data, that is there were only 2 crops included in the analysis.

Table 5. Irrigated faba bean systems.

System	No. crops	Target yield (t/ha)	Yield achieved (t/ha)	Spring irrig (ML/ha)	Extra yield over dryland wheat (t/ha)	Irrigation WUE (t/ML)
Spray	2	4.3	4.9	2.8	1.7	0.6
Flood	4	4.5	4.2	2.2	1	0.5
Dryland wheat	-	-	3.2	-	-	-

*As there were no dryland crops, WUE irrigation response was compared to the average dryland wheat yield of 3.2 t/ha.

Gross margins

The lack of supply led to high prices resulting in high GM/ha and GM/ML. The GM/ML's were similar to the 1.5-2ML wheat system.

The good yields and gross margins, coupled with the need for a reliable yielding and priced legume crop in irrigation rotations, is expected to give confidence to many other farmers to start growing faba beans in 2015.

Table 6. Irrigated faba bean system gross margins.

System	Yield (t/ha)	Price ($/tonne)	Variable costs per ha	Gross margin per ha	Gross margin per ML
Spray	4.9	475	693	1635	407
Flood	4.2	475	617	1378	401

* The average dryland wheat gross margin $495/ha was subtracted from the irrigation gross margins ensuring the GM/ML was attributed to the irrigation

** Actual input costs and prices were averaged for each system, but in reality individual farmer yields, variable costs and prices, and hence GM/ML, may vary widely from the averages

*** The gross margins do not include any allowance for purchasing market water

****Prices were those at harvest but most farmers were hoping to sell at prices over $500/tonne.

Acknowledgements

The Finley Discussion Group farmers who contributed records; Rob Rendell, RM Consulting Group; and Geoff McLeod, Finley farmer/consultant and GRDC Southern Panel member

Contact detail

John Lacy
John Lacy Consulting
0427 311 821
johnmarglace@hotmail.com