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Sharon Taylor, Central West Farming Systems (CWFS), PO Box 171, Condobolin, NSW 2877
- Field peas yielded significantly higher then both lupins and vetch.
- Field peas and undersown barley had significantly higher gross margins than lupin and vetch.
- It terms of gross margins there was no significant difference between field peas/undersown barley, undersown barley/vetch and lupins/vetch.
- When choosing to grow a pulse crop the following management issues are critical: time of sowing, paddock selection, species selection and disease and pest management.
- There was no significant difference between each pulse crop, and their varieties, in the amount of mineral N in the soil after harvest.
Introduction
The Tottenham regional site group, in association with the Top Woodlands Agricultural Bureau, in 2003 investigated the production, management and profitability of three different pulse crops. These pulse crops included narrow-leaf lupins, field peas and vetch, with lucerne undersown in barley used for comparison to a pasture phase.
The main reason for conducting the trial was to determine whether pulse crops could be grown successfully in the Tottenham district and subsequently to identify an alternative crop for the wheat cropping rotation, which usually includes barley, oats, lucerne and/or canola.
Pulse crops in the farming rotation need to be seen as not only a cash crop but also as a "health kick". Pulses reduce disease, spread frost, market and hsarvest risk, help with weed management and add nitrogen into the system. While they can be less profitable in their first year compared to cereals, they boost profits in the next wheat crop so that the overall rotations profit is greater than continuous wheat, with or without applied nitrogen (Carpenter 2003). Subsquently, the second reason for conducting the trial was to measure and evaluate the follow-on effects of pulses on the following two years of wheat in the Tottenham district.
Method
As the trial was investigating different pulse crops, at least two varieties were selected to represent each crop (Table 1). The lupin varieties were selected based on their shatter resistance and disease resistance, the field peas varieties were selected based on their ability to stand at maturity and their height, as an open front header was to be used for harvest. The lucerne and barley varieties were selected based on district experiences.
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Table 1. Crop, variety and sowing rate for the Tottenham regional site pulse trial |
The trial was designed as a randomized, replicated block with 2 replicates. The trial was on a local farmer's property approximately 6 km north of Tottenham on a red brown earth, with the plots 23 m long and 6.3 m wide. As the management on the trial was a key indicator for the performance of these pulses the trial was sown and managed by the local farmer. The lupins, field peas and vetch were sown, with an international combine, on the 8th May 2003, with 80 kg/ha MAP fertilizer (10:21.9:0:1.5), whilst the undersown barley was sown on the 12th June, using the same equipment, plus a small seeds box and fertilizer. The pre-emergent herbicide used was Roundup CT® at 1 l/ha and the growing season rainfall can be seen in Figure 1:
Soil samples (0-10 cm) were taken prior to sowing the trial on the 5th May, the 10-60 cm lay was to be sampled however due to circumstances on the day they were not taken, and on the 29th January 2004 (0-10cm and 10-60cm). These soil samples are to be used to compare the amount of nitrogen in the soil after the growing season from the different pulse crops.
During the course of the trial three things happened that had an effect on the trial results. The first was pest damage from emus. The lupins were eaten by emus soon after germination, with most plants losing their terminal growing point. As the lupins plants matured the emus moved onto green pasture and the lupins were left to pod up quite nicely, however the plants severely lacked height and not all the pods could be harvested.
The second hurdle was the infestation of all plots with wild radish (Raphanus raphanistrum L.). The wild radish was controlled in the lupins and field peas using Brodal® Options, however, it could not be controlled in the vetch and undersown barley.
The third incident was the infection of one plot of Snowpeak field peas with Bacterial Blight. The bacteria which causes this disease is present in most pea-producing areas, however, severe crop damage only occurs sporadically, one in ten years. Bacterial Blight tends to occur with high rainfall, hail, strong winds and low temperatures (Armstrong et al 2001). This year at the trial site the seasonal conditions included strong winds and low temperatures with frequent frosts. The Bacterial Blight nearly halved the yields in Snowpeak with the effected plot yielding 0.62 t/ha compared with 1.1 t/ha in the unaffected plot.
RESULTS
The yield and gross margin results from the pulse trial are shown in Table 2. These results show a significant difference (P=0.01) between the yield of each crop with field pea yields significantly higher than lupins, vetch and undersown barley. There was no significant difference in yields between the varieties of each crop type.
The data also shows a significant difference (P=0.05) between the gross margins of certain crops. Field peas and undersown barley had significantly higher gross margins than lupin and vetch, whilst there was no significant difference between field peas/undersown barley, undersown barley/vetch and lupins/vetch. Again there was no significant difference in gross margins between the varieties of each crop.
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Table 2. Grain yield and gross margin of the Tottenham regional site pulse trial 2003. Note: Numbers with the same letter are not significantly different. |
The 0-10cm soil test results from the Tottenham regional site pulse trial can be seen in Figure 2. These soil tests reveal that there is no significant difference between the pulse crops or their varieties in the amount of nitrate or ammonium (mineral N) in the soil after the growing season compared to the pre-sowing soil test.
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Note: Bars with the same letter are not significantly different. |
DISCUSSION
Given the season in 2003, what really stands out from these results is the yield performance of field peas compared to lupins, vetch and undersown barley. This could be attributed to management issues such as time of sowing and weed management/paddock selection. The ideal sowing times are lupins - April, vetch - May, undersown barley - May/June and field peas - May. Due to a lack of rainfall the lupins were sown later than optimum, which combined with early pest problems, resulted in a poor yield performance. The field peas, on the other hand, were sown at the optimum time (8th May) enabling them to grow and flower before the hot, dry finish in spring.
The yield performance of vetch and undersown barley was effected by wild radish. The wild radish was controlled in the lupins and field peas with Brodal®Options @ 0.2 l/ha. In vetch and undersown barley, however, no broad-leaf herbicides are registered for use and subsequently the wild radish competed vigorously against the vetch.
There was a noticeable variation between the gross margins of the different crops. The variable costs (e.g. seed, herbicide) and the income from each crop contributed significantly to these variations in gross margins.
The soil test results taken in January 2004 reveal there is no significant difference in the amount of nitrate or ammonium (mineral N) left in the soil after the growing season. By comparing the pre-season test results, and the N added in the fertilizer (8 kg/ha ~ 5 mg/kg), with the 2004 results it can be seen that each pulse crop added 2 mg/kg of mineral N. The use of this nitrate by a wheat crop in 2004 will be measured.
- Time of sowing - In low rainfall environment the time of sowing is critical to optimize yield. Lupins need to be sown early, around mid-April.
- Paddock selection - Don't put broad-leaf crops in paddocks with a high broad-leaf weed population, as they are difficult to control. Pulses can be grown to control grass weeds and to rotate herbicides.
- Species selection - Identify the weed population and herbicide options for your paddock before choosing a pulse crop. Wild radish can be controlled in lupins and field peas but not in vetch.
- Disease/Pest management - Farm hygiene is important (i.e. purchasing "clean" certified seed and using seed treatments). Pulse diseases can be managed by species/variety selection, however, for some disease problems, such as bacterial blight in field peas, the cost of control in uneconomical. Pests need to be monitored throughout the season and they can be controlled with insecticides.
CONCLUSION
In conclusion field peas were the highest yielding pulse crop, whilst field peas and undersown barley had the highest gross margins. When growing pulse crops the most important management issues to be considered are time of sowing, paddock selection, species selection and disease and pest management
ACKNOWLEDGMENTS
We would like to thank the TOP Woodlands Ag Bureau for allowing the Tottenham Regional Site to operate in association with them during 2003. We would also like to thank Keith Greig for providing his time, labor and advise with the trial, it was greatly appreciated. Also thank you to Rob Sanderson and Daryl Reardon for assisting with harvesting and soil sampling. Thank you also goes to Nathan Border for his help with writing this paper.
REFERENCE
Armstrong, E., Bretag, T., Ophel-Keller, K., and Panagiotopoulos, K. (2001) Strategies to minimize bacterial blight in field peas. Pulse Point No. 13. NSW Agriculture. Black, A.W. (2000) Extension theory and practice: a review. Australian Journal of Experimental Agriculture 40, 493-502. Carpenter, D. (2003) "Give your pulse a chance!" Central West Farming Systems Field Day Book 2003.
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