Farmers Helping Farmers podcast Episode 2 with Graeme Sait

Internationally renowned nutritionist and farmer Graeme Sait is a wealth of information, and after a tragic family accident, he has dedicated the past 28 years of his life to sharing all that he knows and all that he has learnt about improving plant and human health. VicNoTill is honoured to sit down with Graeme in this episode. He encourages farmers to take small steps towards change and they will reap the rewards, both financially and personally.

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Graeme knows so much about growing nutritious food and we’ve only crammed in a tiny portion of what he knows into this conversation! Don’t forget to tell your friends about the Farmers Helping Farmers podcast and if you enjoyed this episode please leave a review. The more people who join the conversation, the more we learn from each other. Subscribe to Farmers Helping Farmers on your favourite podcast app and connect with VicNoTill by becoming a member and following us on Twitter, Facebook and YouTube.

More about Graeme Sait

In 2020 our board members caught up with Graeme about the basic concepts of nutrition farming – an integrated holistic approach that also includes the connection between soil health and farmer health. Watch the full episode on our YouTube channel.

He also wrote an article for us for the Summer 2022 From the Ground Up member magazine, see below. If you would like to become a VicNoTill member, you’ll receive three magazines a year plus enjoy a whole range of other benefits. It’s a great way to connect with other farmers and share information. JOIN HERE.

The Potential of Pre-Harvest Foliar Nutrition

By Graeme Sait

Attendees at our Carbon Power conference voted Graeme Sait as the number one speaker who generously shared his knowledge and experience during his presentations in the paddock and conference room over the three days. He has also written this article for our magazine, which is something we discussed at great length with him while we had the opportunity.

It would seem obvious that if you optimised nutrition prior to harvest, there would have to be flow-on benefits in terms of subsequent seed quality. However, there is a remarkable lack of research demonstrating this likelihood. This would surely have to be a productive area of research for any Masters students out there looking for a thesis subject. Let’s look at the potential benefits, before we review the limited research available.

The first thing to consider is the simple fact that a large seed will always outperform a smaller seed, Size counts when it comes to yield potential, and the impact of that size differential continues right through to the final yield. Sometimes you have to see something for yourself to truly understand the phenomenon. I grow garlic at one of my farms and it is one of my favorite crops. My interest in this wonderful medicinal bulb was initially sparked when I was presenting at a National Garlic conference. At this event, one of the speakers spoke about her research regarding clove size at planting. Her simple message to the growers present, was to save your largest seed for planting. I decided to test this hypothesis by planting rows of large cloves beside rows of small cloves on one of my research farms. The yield difference was quite remarkable at season’s end. In fact, the percentage of difference in clove weight at planting translated to a similar percentage in end yield. For example, if the seed was 50% smaller at planting, the yield was 50% less. Never again have we saved our best for the market. It always goes back to the paddock.

Pushing seed size

What minerals determine seed size for cereals and legumes? The number one mineral for seed size is potassium. Potassium moves carbohydrates into the seeds, to fast-track their fattening. It’s a little like feeding grain to cattle in a feedlot scenario. Interestingly, there are a growing number of studies demonstrating that foliar potassium out-performs soil applied K fertilisers, and it is much more cost-effective. This was apparent in a Turkish study, published in the Turkish Journal of Field Crops. This paper was entitled Foliar Spray Surpasses Soil Application of Potassium for Maize Production under Rainfed Conditions.

Here, they showed that foliar applications of 3% potassium generated impressive yield increases. These foliars performed much more efficiently, and in a more cost-effective fashion, when compared to side dressing of potassium. I have sung the praises of the foliar spraying of potassium sulphate at 8kg per hectare for quite some time. In this context, it was pleasing to recognise this particular rate roughly equates to the 3% potassium that proved so effective in this study.

Silica for size and resilience

The second consideration to improve grain size is silica. Silica improves nutrient translocation throughout the plant, including into the seed. There have been several studies reporting generalised increases in mineral content, following silica applications. One Egyptian study looked at maize response to foliars of potassium silicate. They found that 1% potassium silicate (1 litre per hectare, in 100 litres of water) was particularly productive. In fact, they chronicled significant increases in plant height, ear length, ear diameter, grain weight and grain and straw yield, following three foliar applications of potassium silicate. The other impressive outcome from this silica study was the substantial increase in water use efficiency, associated with these silica foliars. That sounds like something of immense value in Australian dryland farming. NTS has developed a high performance Potassium Silicate foliar, that has become one of our major export products.

Trace minerals pay dividends

The trace minerals most linked to grain size are two trace minerals, commonly lacking in broadacre crops. These missing minerals are manganese and zinc. Both of these minerals have important roles in nitrogen metabolism, and that may be their major link to seed size. However, this productive duo offers more than larger seeds. They actually provide a double whammy, as they both enhance seed germination and boost early growth.

Manganese is of particular interest here. It is no accident that manganese has been termed ‘the seed energiser’. In fact, this mineral should always be an essential component of any good seed treatment formula. The importance of manganese for seed formation is probably best exemplified by seedless watermelon. They are a product of a hybrid than cannot uptake manganese. You shut down manganese and there is zero seed production.

Zero-till growers have another issue to consider, relative to ensuring sufficient manganese at the business end of the season. Glyphosate kills the organisms responsible for the plant availability of this mineral (manganese-reducing organisms). This herbicide was first developed as a chelating agent to strip manganese from the inside of boiler stacks in heavy industry. This powerful chelating capacity can also lock up manganese, so glyphosate actually delivers a double hit. There are now several papers demonstrating a dramatic reduction in manganese uptake associated with this twin hit. The key is to compensate with a foliar spray of one kg of manganese sulphate per hectare in 100 litres of water, with 300 grams of soluble fulvic acid powder, preferably after flowering.

As mentioned earlier, there is a marked scarcity of research into producing better seed with pre-harvest foliars. However, I was able to locate a broccoli study which examined the impact of foliars on post-harvest, quality parameters. Broccoli is a seed head, so it is a reasonable to assume that these findings would relate to the seed quality of any field crop.

In this brassica study, calcium, zinc, manganese and iron were foliar sprayed before harvest, and their impact assessed. The nutrients were applied separately at concentrations of 1 gram per kg. If we were considering calcium, for example, that 1 gram per kg rate would equate to 2kg per hectare of calcium nitrate in 400 litres of water.

All the treatments in this study increased key crop quality parameters like total phenolic compounds, ascorbic acid, chlorophyll content, flavonoids and the antioxidants of glucoraphanin and glucobrassinin. However, the treatments involving foliar calcium and manganese also increased protein levels and the levels of the all-important protectant, sulforaphane.

That highlights the one other mineral that would be of benefit in pre-harvest foliars when trying to improve seed quality and performance. Calcium foliars can increase crop quality in all crops, so it would seem logical they could boost seed quality. The simplest and most cost-effective solution here would be 2kg of calcium nitrate per hectare with 200 grams of soluble fulvic acid powder.

In conclusion….

Despite the complete lack of research into the benefits of pre-harvest foliars to lift seed value, it is clearly evident this strategy would be of benefit. You can boost seed size with potassium, seed development and fertility with manganese, seed resilience with silica and seed quality with calcium. In fact, pre-harvest foliars can almost be seen as ‘mothers milk’, to nurture the next generation.