IRRI Agronomy Challenge 2: Getting started again – what we’ll do differently

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Achim Dobermann & Leigh Vial

December 5.

Achim enlisted the help of Leigh to embark on a challenge to see for themselves IRRI's technologies in action. 

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A year ago, we grew a crop of rice, hoping to apply good management practices to achieve a high yield, high profit, and high input-use efficiency. These are not mutually exclusive goals in modern agriculture. In fact, that’s the kind of triple Green Revolution that will be needed to produce more rice in the future, do it in a more resource-efficient and sustainable manner, and thus also make it a more attractive local business opportunity for young people. Unfortunately, in our first attempt, we didn’t quite get there. Instead of the 7 tons of paddy per ha we had planned for, we harvested only 5.2 t/ha. We managed to obtain a profit of US$335 per ha, but that wouldn’t be enough to make a decent living from farming, certainly not in the future.

We’ve carefully analyzed the many reasons for our failure. Some were our fault and inexperience; some were just bad luck, such as poor weather.

Farming is all about continuous learning and behavior change, so we’re sure that we can do better. We started talking about the upcoming growing season two months ago because preparing for a crop to grow must also take into account the period before, to get the land into good shape. Our plans follow:

Leigh Vial and Achim Dobermann contemplating land preparation.

Leigh (left) and Achim (right) contemplating land preparation.

    1. This time, we’ll grow a machine-planted rice crop because mechanized transplanting is a labor-saving technology that is proven and also spreading widely now in various countries of Asia, where small entrepreneurs are beginning to offer such services to smallholder farmers. It is a shame we are forced to transplant at 30-cm row spacing, as that is all that is available here currently, but that, too, is changing and very soon machines with closer row spacing will be required; 20–25 cm would be better. Wet-seeded rice as we tried last year seemed more difficult to manage, so we’ll go with a safer bet now.
    2. We will do less intensive and less deep land preparation than last year. All we need to accomplish is to incorporate residue and make the soil soft and level enough for planting. A wet-season rice crop was harvested in mid-October, after which the field was left fallow. We applied glyphosate once to burn down the vegetation cover that had grown since harvest (rice seedlings, rice rations, and weeds), followed by a light plowing and harrowing of the field with a 2-wheel tractor typically used by farmers in Asia. As it looks right now, we may need to do only another light leveling pass in about a week to get the field smooth enough for planting. One strategic herbicide application has saved a lot of cultivation. We were just out there and it is an amazing difference from a year ago: instead of sinking in to our knees, we can easily walk through the field. That should make many operations easier for us, and better in quality.
    3. We’ll plant earlier than last year, in mid-December, because we know that this typically results in the highest yield potential in the dry season at our location in Los Baños. We don’t know what the actual weather will be like, but, based on the historical weather patterns of the past 20 years, that choice of planting date is our best bet. It is looking drier than last year, with the Pacific Ocean in a more neutral weather pattern as opposed to the La Niña event last year. Of course, we also just want to get it done and out of the way before Christmas.
    4. We’ll grow two new varieties. One will be a recently released high-yielding IRRI inbred variety. The other one will be a recently released IRRI hybrid rice variety. Why? Because we want to know whether we can get some extra yield and profit by growing a hybrid, a technology that is now also spreading fast in many Asian countries.
    5. We’ll make only minor adjustments in our fertilizer management strategy because we think that this component worked quite well last time.
    6. We’ll improve water control to have a better chance to do proper water-saving, and use alternate wetting and drying irrigation if we have less rain.

Achim Dobermann and Leigh Vial inspect rice field

IRRI's head of the experimental station, and head of research inspect the field before the challenge.

  1. We’ll try to pay more attention to pest management. Weed control will be better because we have paid more attention to fallow period management and because we grow a transplanted rice crop with easier water control. Birds won’t be a problem early on because this time we will transplant rice seedlings as opposed to broadcasting seed on the surface. But, we need to watch out for snails and rats, which caused quite some damage last year, and we need to get a better handle on concrete insect control decisions. Last year, we didn’t spray any insecticides, but we had yield losses and still need to decide whether we want to use a more prophylactic control strategy or not.
  2. We hope to avoid lodging of the crop and thus avoid the large grain losses during combine harvesting that plagued us last time.

So, at least in our mind, the plan is clear. The reality will, of course, teach us many new lessons. We’ll keep you posted.


About the Author

Dr. Achim Dobermann

Dr. Achim Dobermann

Achim is a soil scientist and agronomist with 25 years experience working in Asia, North America and Europe. He is recognized internationally as an authority on science and technology for food security and sustainable management of the world's major cereal cropping systems. He has authored or co-authored over 250 scientific papers and two books on nutrients in rice and has received numerous awards from various academic, government and industry organizations. He is a Fellow of the American Society of Agronomy and a Fellow of the Soil Science Society of America.

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