March 4, 2013

Agricultural history. Professor Martin Jones. Lecture notes 1

Professor Martin Jones.  Kings College,  Newcastl Upon Tyne, University of Durham.

 By Dr Deric Charlton

In the late 1950s I was one of those privileged to study pasture agronomy under Professor Martin Jones when he held the Chair of Agricultural Botany at Kings College, the Newcastle arm of Durham University. He inspired me to follow pasture agronomy in my career and I kept the notes I scribbled down in his lectures. Clive Dalton has asked me to transcribe them into a relevant form, so I hope you learn from them as I did.

How plants grow
All our energy needs come from green plants through oxidation of carbohydrates and proteins, with plants taking in nitrates, phosphates and other nutrients, together with more energy from the sun.

Most farmed plants are used by the farm livestock before humans obtain this energy. The animal uses three-quarters of the plant energy in digestion, the remainder being stored as meat. Meat is more suitable for Man as it supplies more energy in a short time. Besides we cannot digest the fibrous plant material whereas they can, and they return the energy they use up to the soil in manorial form. When it is oxidised by bacteria it can then be re-used by the plant.

When a seed germinates, only oxygen is needed to release energy for synthesis (building reserves). Carbon dioxide is then needed for building sugars as the seedling develops green leaves. The longer the plant remains growing in the leafy stage, the more energy it stores.

Using energy
When a plant enters its reproductive stage it uses more energy than it stores. Cereals, for example, are very rapid developers and can be harvested within a year, so are very widely grown in tropical areas where adverse conditions are more prevalent. In the temperate zones however, more energy can be obtained by keeping plants in the leafy or vegetative stage, as they are always building up energy stores and not breaking them down.

Plant behaviour
When plants are establishing from seeds much energy is used, so bigger seeds grow stronger seedlings – “well begun is half done”.

When pasture plants are in the leafy (vegetative or tillering) stage energy is being collected and stored. Tillers (branches) are produced by a grass plant when conditions prevent stem production – usually in early spring. So tillering is a means of storing energy in a pasture.

When pasture plants enter the reproductive stage (during mid-late spring) tillering stops and energy is used to develop flowering stems.

So for effective pasture management, the farmer must maintain leafy pastures and prevent them entering the reproductive stage. At the same time it is important to prevent over-grazing.

Plant types
All plants can be regarded in two forms:
  • Trees, shrubs and herbs.
  •  Annuals, biennials and perennials.
A plant’s growth stages are controlled from within the plant, but this control responds to external factors:
  • Food supply from soil and air.
  •  Water and air supply.
  • Freedom from acidity.
  • Light.
  • Temperature.

Manurial ingredients must be in a soluble form to enable the plant take them in. Carbon dioxide is needed from the air for photosynthesis (food manufacture in plants). Water is needed for food transport through the plant but soil drainage is essential so that air can reach the roots.
Excessive acidity slows down food intake, and much lime is needed to prevent soil acid build-up (far more than is need for food).

Light is the source of energy for the plant to manufacture food. The intensity and duration of light. Intensity is more important during winter whereas duration of light in summer months allows most of the energy to be made and stored.

The critical day temperature is 5ºC as below this level the plant ceases food storage. In summer, temperatures above 40ºC are too high for food manufacture in plants, but around 25-35ºC is just right, although higher temperatures make plants age quicker.

Plant scientists use Accumulative Temperature to measure Day-degrees, the temperature quota needed for a certain growth stage. This is usually measured as the number of degrees over 20º C, so on a day that the temperature reaches 30º the AT is 10, and on a day that the temperature reaches 40º the AT is 20. Plants have different AT requirements, so if Plant A ripens before Plant B, the first plant will have reached its AT requirement before the second. For example, oats need 800 day-degrees from brading (breaking through the soil surface) to ripening, and this is the same in a hot season as it is in a cold one.

Day-degrees therefore determines whether a ryegrass is early or late-flowering. It regulates the suitability of a particular crop to a region. In Britain for example, oats grow best in the cooler regions of Scotland, whereas wheat grows better in England’s southern regions.

Temperature and pasture growth
Soil temperatures (in the top 10cm) affect pasture plant growth very much. When a farmer sows a new pasture the seeds germinate much faster in warmer soils, although perennial ryegrass and white clover will still emerge much quicker than other species, which is probably a major reason for their popularity with farmers – they are easier to manage. (NB. More drought-tolerant grasses like tall fescue and cocksfoot emerge much faster in warmer soils so are best sown earlier in autumn or later in spring than ryegrass -DC)

Leafy Growth in Grasses
The tillering (branching) process is very important in grasses. Every year a grass plant develops new tillers, so a plant may be 20 years old but is physically only a year old.

Pasture plant breeders have revolutionised their variety development by taking advantage of this feature, greatly diminishing the annual/biennial/perennial classification. For example Italian ryegrass is now available in forms that grow high yields of digestible foliage for several months, up to forms that persist several years but spread their production over these years.

The livestock farmer’s aim with pastures should be to maintain as much as possible out-of-season leafy growth, and to obtain leaf production in late spring/summer when the pastures are impelled into stem growth.

Managing the pastures using the livestock, and sometimes silage-making equipment, is the way to influence the form of pasture growth.

However farmers must realise that it is very difficult to graze off all primordia from a pasture.

A hard-grazed pasture (to remove the primordia) will just go to head if it is rested. A pasture should therefore be rested while the grasses are still in the leaf-producing stage (early spring rather than late spring). This has a bearing on what pasture species should be sown and grown.

The earliest spring-growing grass is tall fescue, closely followed by Italian ryegrass. Perennial ryegrass then starts growing as the spring develops, followed by timothy and cocksfoot, and in Britain, meadow fescue is the latest to grow, along with browntop (Agrostis).

Late-flowering perennial ryegrass types are good summer growers as they remain leafy longer, but avoid resting for a silage cut as the aftermath can become stemmy. The early-flowering perennial ryegrass types are best for aftermath growth following a silage cut, as the primordia are removed in the cut. In late summer grasses will stay leafy as conditions prevent seedhead production then (but watch out for dry/dead pasture as it can harbour fungal spores that cause animal disorders - DC).

The earliest developing grasses tend to grow later into autumn/winter. In Britain late-flowering perennial ryegrasses tend to remain more palatable to stock than the early-flowering perennial ryegrass types, because the latter tend to brown off earlier. At the Cockle Park Research Station in Northumberland grazing animals were put on two pastures – one comprising early-flowering perennial ryegrass and the other late-flowering ryegrass, and they all eventually settled on the early-flowering ryegrass sward. However, with this treatment the late-flowering ryegrass pasture would persist longer (it would be less stressed when the environment is also putting pressure on it – DC).

Exploiting the Grasses

The grazing animals on a farm must always come first – but pastures then take the second place. Remember that labour and storage charges for silage and hay treble the cost of livestock feed from pasture.

When grass growth begins in early spring, new shoot growth saps the root system, but they soon start to manufacture food for the roots, replenishing that lost. In autumn the old roots act as storage organs.

Italian ryegrass is the first main grass to wake up, in early spring as the country begins to warm up again after winter. Perennial ryegrass flows about a month later. In these grasses there is a top-to-root balance year-round, one system replenishing the other once its growth has begun. The other permanent grasses, like browntop survive for centuries because they begin their growth later in spring when grazing stock have plenty to eat, and their nutrient stocks can be replenished easily.

The earlier a grass starts growing in a grazed pasture, the more it is exploited, and the more exploitation it has, then shorter its lifespan tends to be. Early-growing grasses like Italian ryegrass should therefore be rested before late spring to let them recover for later use. A one-month rest while it is still in the leafy growth stage will enable it to rebuild its energy bank. A livestock farmer does this by managing his animals, not often realising what he is doing is benefitting his pasture as well.

However, compensating the grass exploited early in spring will only work when no later-growing grasses are present in the pasture mixture. If a farmer wants perennial ryegrass to persist, then avoid including cocksfoot in the seeds mixture. In a Cockle Park seeds mixture (ryegrass, timothy and cocksfoot with red and white clovers) the ryegrass tends to be grazed off during the first growing season, the cocksfoot is grazed off the next year and the timothy goes in the third year when meadow-grasses begin invading. Simpler seeds mixtures with one ryegrass and one clover variety, will probably resolve this sequence.

On a typical upland farm with 800ha of hills and maybe 15ha of lowland pasture a farmer will carry around 400 ewes on the hills from late spring to autumn, and then bring them down to overwinter on the lowland block. At the same time he will graze cattle on the lowland pastures to prevent seedhead development, at the same time returning droppings to the land. The block would be rested from late summer until late autumn, allowing the pasture to age a bit so that the returning sheep won’t develop bloat and replenishing root nutrient storage. Then in early spring the new tiller growth will help to feed the ewes and their lambs. This illustrates good pasture exploitation.
Two British pastures sown to cocksfoot and growing into their third year, were managed as follows:
Pasture A was grazed from March to mid-May, rested for six weeks and then cut.
Pasture B was rested until mid-May, cut and then rested for six weeks.

In Pasture A the flowering buds (primordia) that form seedheads were below the grazing level so they grew during the rest period and produced stemmy poor-quality hay.

However with Pasture B the primordia were above cutting height and were therefore removed when cut for silage. New tillers were developed in the rest period following cutting, so the “aftermath” growth was all leafy – it takes at least six weeks for a grass tiller to develop another primordium.
Professor Martin Jones. 
The thin chalk line - Memories by Clive Dalton (1952-56).

Botany – of the pure kind
For those of us who whose main interest was farm animals, and had never done botany at school, having study it in the Intermediate year of our degree was somewhat of a chore (to put it mildly). Botany labs in the old Armstrong College building were not taken terribly seriously.  Having to cut up a pansy and draw its vital parts was a bit too far from growing oats, barley and turnips which fed stock – pansies didn’t.

Professor Merion Thomas we all thought was mad!  He taught plant physiology and could write on the blackboard without looking at it.  By the end of the lecture, the board was a total incomprehensible mess.

But we admired the sincerity of lecturers like Dr William Clark, husband or our dear ‘Dolly’ (a Geordie) who took us for agricultural botany in our second year.  A true Scott, I can still hear Dr Clark’s Ayrshire tongue with the common speech habit of precise thinking Scott’s of inserting ‘aaay’ between every 2-3 words while their brains searched for the precise word. We used to call him ‘Dr aaay Clarrrk’.

We got good at predicting when he’d insert an aaay. For example he’d always start a lecture with a wee synopsis of what was on the menu:

‘Today aaay, we’re going to aaay, discuss aaay, the function aaay of the parenchimatous barrrll shaped cells.  Last time you will aaay remember that we aaay …………….

Agricultural botany
But at last in our second year, we were with our own kind – agricultural botanists, who quickly made us realise that Ag botany was a massive subject on its own, and not just a tack on to pure botany.  

It had the key role of feeding the world from the beginning of time, and Dolly Clark was a world expert on ancient cereal grains and their growing as the start of this.

Professor Martin Jones 
When we met Prof MJ who led the College’s Agricultural Botany Department, I suppose he’d be in his 60s with graying hair and mustache. His classical mid Wales accent (Welsh was his mother tongue) was an inviting target for mimicry, a habit for which some of us were too prone.

But the great thing about this was that by imitating his words, - and they were always precise uncluttered with jargon – we learned them never to be forgotten.  Later in Wales, I was to learn that it was the style of a rousing sermon in a Welsh chapel. 

Many of the word intonations between Geordie and Welsh are very similar, especially the rising inflection at the end of a sentence, and I used this trick some four years later when I went to Bangor in North Wales to do my PhD. The local Welsh speakers thought I was from South Wales (and not English), so was readily accepted among the College farm staff – and the farm dogs who had no English!

Prof’s lectures
We knew the drill to so many of Prof’s lectures. He would come into the lecture room on the second floor of our Ag building, taking small steps with his stick, always in a 3-piece suit, and wearing his Homburg hat which he always removed carefully.  His faithful walking stick was rested along the front of the bench, and regularly became a handy pointer for extra emphasis.

The thin chalk line - birth to death
Inevitably early in his lecture Prof would draw a long thin line in chalk, right across the length of the very worn blackboard.  This represented the surface of the ground.

Then the story would begin –told with the passion that only Welsh speakers can put into the English language.  In no time he had us captivated as the story would start to build – always from left to right on the board.

The ‘seeede’
On the far left, the chalk made a tiny speck on the board just below the line, and then with a few more tiny circles a ‘seede’ would appear, nicely covered by enough soil to give it protection and keep it moist.  Never ‘too deeepe’!

With a bit more chalk work it would fatten, and suddenly a ‘shoote’ would burst from it and fight its way upwards to the surface.  Then with more chalk work, from the seed’s base, a tiny ‘roote’ - a ‘seminal roote’ appeared to fight its way down.  Why did the shoots know to go up and the roots to go down?

Then we remembered in those dry pure botany lectures, all that stuff we got the clever chemistry involved in why shoots go up and roots go down.  It was useful after all. 

So now from Prof’s lectures we appreciated that if you got the seed depth wrong when setting the drill and the subsequent harrowing, you could cause serious trauma to this germ of life – and cost to the farmer (your employer).  You may not be there long!

The ‘shoote’
Then with his dark Welsh eyes sparkling, as we sat there we saw the shoot start to make its hazardous journey up above the chalk line breaking through the surface to life support from the sun. We felt like shouting ‘Halleluiah’. 

Things were moving fast now, as the shoot started to ‘tillller’ – with more young shoots starting to emerge out of the plant’s vitally important ‘growing point’ just above the ground surface.  This was a sacred part of the plant and must never be damaged – we got that message in no uncertain terms!

Prof’s excitement gained momentum as his chalk produced more shoots (tillers) and more roots – and more roots and more shoots.  He was in full flight until suddenly - Silence!  You could hear a seed drop.  He had our total concentration - we were all hooked. 

What on earth could have happened of such momentum to this chalky grass plant growing along our well-worn blackboard, to bring our normally relaxed mob to total silence? 

With his back partly hiding his hand doing a bit more secret chalk work – there it was.  The first ‘seeede head’ – the grass flower.   We all cheered!

Prof’s chalky masterful hand produced more and more seed heads on the plant which ‘greewe’ quickly – even in a matter of days when light, temperature and nutrients were all in line. 

We animal men all knew that sex had few downsides apart from a few disease risks, and you could never get enough of it, and he cunningly led us to believe that sex was what the plant wanted too. We were all very keen to support the idea.

But then our blackboard plant with its massive seed heads started to look tired and stopped growing!  Maybe there was a lesson here that too much sex could have it’s problems.  So as more flowering heads appeared with their mass of developing seeds, the plant leaves started to droop, get narrow and fall over.  Then some of the seed started to drop out. 

So now our great grass plant full of vigour in its youth was on death row!  With Welsh passion in his voice – he almost had us all in tears.  After sex you could die – and if conditions were right – you could die fast!  We could imagine a little white cross as the last drawing on the line.

But there was salvation!
Indeed there was salvation for our chalky blackboard grass plant.  With more sparkle back in his eyes and bending slightly forward while eyeballing everyone one in the room Prof asked in his rising Welsh tones –“So what happens then’?  We were all on tenterhooks.

With a wide sweep of his arm and a slowly closing fist, Prof hit the blackboard just before those sexy seed heads had appeared and grabbed at the lush and leafy chalky plant and decreed – ‘the cattle beast takes it all’!

Then with his duster he wiped the top of the chalky plants and we thought he’d ruined his masterpiece and all the work that went into it.

Like a final blessing in a Welsh Chapel he thundered - ‘Always aim to keep the plant in the leafy vegetative stage’– and in almost a whisper he continued - ‘by good grazing management’.   His Gospel continued with - ‘The grass plant feeds the animal, and the animal keeps the plant to keeps it its vegetative stage’. 

The other key part of this great grassland Gospel was that no matter what grass varieties you sowed, if you didn’t get the animal defoliation business right, you’d end up with a mess of unproductive grasses, no clover and weeds. (See Deric Charlton’s notes).

One day before Prof arrived at class, we had the thin chalk line already drawn on the board for him – with one addition. One of the lads drew an enormous leek at the far right hand side of the board, correct in every botanical detail.  It was a wonderful specimen that would certainly have won the Supreme Award and Cup at the Bellingham and District Annual Leek Show, and probably would have taken out the cup at Ashington Miners’ Leek Show too.

Prof came in, and to our utter dismay and great disappointment completely ignored it.  We were starting to feel a bit peeved, and accepted that our smart-ass move had flopped.   We knew that these things happen of course, with lecturers who have their good and bad days!

The thin chalk line got its usual workout, and it was getting near the end of the lecture when most of us had entered that twilight zone of concentration, brought on by lecturers repeating their message for at least the third time.  We drifted on to the importance of nutrient storage and feeding value, and how to make sure the nutrients were used for the stock and not wasted to produce seed.

Prof was chalking away on the topic, watching our reactions at the same time - and then suddenly he stopped.  Silence!  Prof picked up his Homburg hat grabbed his walking stick and headed for the door.  Our clicking ring binders celebrated the end of proceedings - but to our dismay - he had stopped dead in his tracks.

He spun around, eyes sparkling, moustache bristling and in a crouched pose, with stick at the ready as a pointer and grin as wide as the Tyne - he hollered in his great Welsh accent - ‘LIKE THE FOOD STORE IN THIS LEEEKE’ !

He bolted shaking with laughter to our roar that would have done a Jackie Charlton header proud.  Full time score that day: Martin Jones 1 – Students Nil!

It was at the end of so many of Prof’s lectures that I used to panic – I hadn’t written anything down!  The standard routine in lectures was from when the lecturer first opened his or her mouth, to when they thankfully left the room at the end, it was wise to write down every word they uttered.  You dare not sit back and listen, hoping for a clear message to regurgitate back to them in exams. 
Most times there was no clear message!

In Ag economics lectures I found that when I finally faced the agony of reading the scribbles of my Parker 51 fountain pen before an exam, the notes went around in a complete confusing circle, as those from the last lecture seemed to be a repeat of those from the first!  It all seemed ‘common sense made difficult’ – a good definition of economics at the best of times, but it was essential to regurgitate in exams what you got in the lectures if you wanted to pass.

With Prof MJ, all that most of us had to show for his hour’s lecture was a line across our books with little drawings on it.  But really you didn’t need notes – it was all there from his skill or an orator, turning words delivered with passion into images, which most brains can recall better than text.

My future salvation - Prof’s chalk line.
Sixty plus years later as a Scientific Liaison Officer at the Ruakura Research Centre in New Zealand we received many VIP overseas visitors, who had come to New Zealand to see how we produce and manage pastures.  They wanted to find out how to keep costs down for their farmers to stay in business - to crack the secrets and dark arts of Kiwi pasture management.

Then later in the 7 years I taught pasture management to young farm Polytech students, most of whom were full time on the farm, only coming to class one day a week – I had really needed some tricks. 

These part-time students were always tired as they worked awful hours, and from their school background they were not great note takers. I could get them to draw pictures and use mind maps where writing was at a minimum.  The challenge was to make the science behind the practice of farming interesting and relevant – to explain the Why behind the What.

Prof MJ’s thin chalk line said it all.  After all those years I could remember every detail, and I unashamedly used all the tricks of the great man, to get the basic message across so they went back to milk at least motivated to want to learn more.  The details of strip grazing and rotational grazing, feed allocation and feed budgeting were not the main issue – the basic principles were. 

It was getting these students to appreciate, value and marvel at ‘the green stuff’ the cows ate and dunged on.  I used Prof’s thin chalk line (now with a whiteboard marker) to get them to remember (and never forget) how a grass plant started life, how it lived and died – and how important this was to their farm income and the economic benefit of every New Zealander.  It’s a pity that most politicians both then and now had no idea what all this was about.

New Zealand pasture knowledge for export
In recent years there have been many more overseas farmers and executives from dairy companies coming to New Zealand to learn about our pasture management, as their high cost systems based on grain feeding are now starting to hurt their profits.

They have suddenly realised that pastures can be much more than summer exercise areas for their monstrous grain-devouring North American Holstein Friesian cows, which have swept throughout the world.

Pasture management is not an easy subject to teach, as when you visit successful New Zealand farmers and hear them talk about what they do to achieve top results, it sounds to be more art than science.  So much of it is about timing of doing things like moving fences and moving stock.

There’s a question of – ‘what’s the difference between a good Kiwi farmer and a poor one’?  The answer is – ‘about a week’!  This is because the grass plant as a feed source varies every day of it’s life in both quantity and quality, and even over different parts of the day.

Teaching pasture management through a translator is always a frustrating and worrying business, as you never quite know if your message was clear.  Prof MJ’s chalk line always saved my day an at times I found myself slipping into bits of passionate Welsh if I was concerned about the translation accuracy!   I loved walking around the class sneaking a look at visitors’ notes and seeing Prof’s thin chalk line being annotated in Chinese, Japanese, Korean and Spanish.  I wish he could have seen it all – I certainly felt his presence.

My 1953 Ag Botany my lecture notes from Kings had long gone – but I didn’t need them.  Because of the skill of Prof Martin Jones as an inspirational teacher, it was all there as a picture in my old brain.