No matter how much sodium one puts into a sand rootzone, the soil structure cannot be affected, so gypsum won’t be required

I received this question about leaching salts from the rootzone: “I remember talking to you once before regarding flushing excess salts from the root zone and the application of gypsum or other calcium products before the flush and you telling me it was not necessary. I have since discovered that same conclusion for myself. I… Continue reading No matter how much sodium one puts into a sand rootzone, the soil structure cannot be affected, so gypsum won’t be required

“Don’t try to jump on his bandwagon”

Jon Scott wrote to me about my recent post on a poor way to fertilise. “While this superintendent has solved his problem of nitrogen input by monitoring salinity level that has worked for him, this is probably a very unique situation. It may be relevant to other golf courses where similar salt levels exist, but… Continue reading “Don’t try to jump on his bandwagon”

“Is there a particular reason why you think it’s a poor way to fertilise?”

A correspondent wrote: “I’m hoping to get your thoughts on something I came across today. I was discussing greens fertilising whilst at a friend’s course this morning. He went on to get his new toy, the […]. He’s started to use the salinity level reading as an indicator to fertilise. So he’s found a number… Continue reading “Is there a particular reason why you think it’s a poor way to fertilise?”

MacKenzie’s fundamental principle of greenkeeping

I taught two seminars yesterday at the Philippine Golf Course Management conference. The first was about irrigation water requirement. The slides are here, and I made this Shiny app with data from 2013 through 2016 for Manila, Cebu, and Baguio. In the second presentation I spoke about MLSN after 5 years. I explained what soil… Continue reading MacKenzie’s fundamental principle of greenkeeping

This surprised me

I was making some calculations today about irrigation water requirement. I looked at Manila, where the normal annual rainfall is 1877 mm, and Cebu, where the normal annual rainfall is 1260 mm. These data from Manila are the 30 year average from 1961 to 1990, and at Cebu a 20 year average from 1971 to… Continue reading This surprised me

A Shiny app with adjustable rootzone characteristics and irrigation rules

I made this Shiny app that calculates the daily soil water balance. The idea of the app is to change the soil conditions, specifically the rootzone depth and the field capacity, to see how changes in those parameters influence the irrigation requirement. And the irrigation "rules" can be changed too. When will irrigation water be… Continue reading A Shiny app with adjustable rootzone characteristics and irrigation rules

Estimating irrigation water requirement for different soil conditions

In previous posts, I wrote about the daily soil water balance and irrigation frequency using Bangkok (DMK) weather data, and showed how changes in irrigation “rules” can change a predicted irrigation water requirement, that time using Phuket (HKT) weather data. Thailand conveniently has golf courses adjacent to many of its major airports, so I can… Continue reading Estimating irrigation water requirement for different soil conditions

What happens to the irrigation water requirement after changing the irrigation “rules”?

I’ve shown how calculation of the daily soil water balance, matched to precipitation data, can be used to estimate the irrigation water requirement for a given set of irrigation “rules.” That is, if I calculate how much water is in the soil (details about the calculation method here), carefully adding in the amount added by… Continue reading What happens to the irrigation water requirement after changing the irrigation “rules”?

Simulating irrigation frequency at the world famous “snake” course

The “snake” course, and simulation using the daily soil water balance Many of you will have seen the Kantarat Golf Course when flying into Bangkok. Maybe you’ve played it. It’s a cool course, set between the two runways at Don Mueang International Airport in Bangkok. It is commonly called the snake course, and I can… Continue reading Simulating irrigation frequency at the world famous “snake” course

My presentation on irrigation water quality

Yesterday I taught a seminar about irrigation water quality. Here are some links related to that presentation. View or download the presentation slides here Harivandi’s Interpreting turfgrass irrigation water test results Bicarbonate does not seal off the soil My presentation handout from the 2014 conference on Soil and water management: 3 problems, 3 solutions A… Continue reading My presentation on irrigation water quality