Prasad Stopped Feeding His Paddy All at Once

For twelve years, Prasad fed his paddy the way his uncle had taught him: generously, and early.

Three weeks after transplanting, when the labourers were free, he would broadcast most of the season's urea in one go. Within ten days his four acres near Kovur in Nellore district would turn a deep, glossy green, the darkest field along the canal. "Like a carpet," the neighbours said.

Then the trouble would start. Brown planthoppers at the base of the plants, hiding where the crop was too thick for sunlight to reach. Blast spots on the leaves in the cool weeks. And in the last month, when the grain was filling and the evening winds came off the coast, whole patches would lodge, flat on the ground, grain sprouting in the wet.

Last season he lost close to a third of one field to lodging, and his pesticide bill was longer than his fertiliser bill. At a Krishi Vigyan Kendra training session, he described the problem. The scientist asked him one question.

"When does your paddy need the most food?"

Prasad did not know. Nobody had ever asked him.

"The plant doesn't eat when you are free. It eats when it is hungry. Your job is to know when that is."

What are the growth stages of paddy?

Paddy grows through three broad phases: the vegetative phase when it builds roots, leaves and tillers; the reproductive phase when it forms the panicle and flowers; and the ripening phase when grain fills and hardens. Each phase has different needs.

Within those phases, these are the stages a farmer can actually see in the field:

1. Nursery. Seedlings grow in the nursery bed for a few weeks before transplanting.
2. Transplanting and establishment. The seedlings recover from the shock of being moved and start new roots. Yellowing for a few days is normal.
3. Tillering. Each plant sends out new shoots from its base. More healthy tillers means more panicles later. This is when the field "fills up".
4. Panicle initiation (PI). Inside the main stem, invisible from outside, the plant starts forming the young panicle. This is when the number of grains per panicle is being decided.
5. Booting and flowering. The panicle swells inside the leaf sheath, then emerges and flowers, usually in the morning hours.
6. Grain filling and maturity. The grains fill with milk, then dough, then harden and turn golden.

The length of the vegetative phase depends on your variety's duration. But for most varieties, the reproductive and ripening phases take a similar length of time, so panicle initiation usually comes roughly two months before harvest. Ask your seed dealer or officer for the timing of your specific variety.

Why is nitrogen split instead of given at once?

Because the plant can only use nitrogen at the rate it is growing. A young crop with small roots cannot take up a large dose, so much of it is lost to the water, the air and the weeds. Splitting puts nitrogen in the soil just before the stages that need it most.

The common pattern is a part at planting or soon after, a part during active tillering, and a part around panicle initiation. How much goes in each round, and the total, should come from your soil test and your agriculture officer's recommendation for your variety and season. Some recommendations also include potash around panicle initiation.

Prasad's one big early dose produced soft, leafy growth and too many tillers, many of which never carried a good panicle. By panicle initiation, the nitrogen was largely gone. He had fed the plant when it was a baby and starved it when it was deciding its yield.

What happens if you miss panicle initiation?

If nitrogen runs short at panicle initiation, the plant forms smaller panicles with fewer grains, and that loss cannot be made up later. Fertiliser given at flowering or grain filling comes too late to add grains that were never formed.

The difficulty is that panicle initiation cannot be seen from the road. The field looks the same as it did the week before. Here is how to catch it:

• Count from transplanting. Note the transplanting date and your variety's duration, and work out the expected week.
• Split a stem. Pull a few main tillers and slit them lengthwise near the base. At panicle initiation you will see a tiny, fuzzy, whitish tip, about the size of a grain of rava.
• Watch the leaf colour. A leaf colour chart, available from many agriculture offices and KVKs, lets you compare the youngest fully opened leaf against standard shades to judge whether the crop needs nitrogen.
• Check a few spots, not just one corner. Different patches can be at slightly different stages.

How do you know you have given too much nitrogen?

Too much nitrogen shows up as a crop that looks wonderful in the middle of the season and causes trouble at the end. Watch for:

• Very dark, droopy leaves and a dense canopy you cannot see through
• Many tillers that stay thin and never carry a full panicle
• More brown planthopper, leaf folder and blast, which thrive in soft, crowded growth
• Lodging in the last month, especially after wind or rain
• Delayed maturity, with the field staying green longer than neighbours planted on the same day

If you see these signs, don't add more nitrogen. Ask your agriculture officer about pest scouting, and plan better-timed splits next season.

How Prasad times his fertiliser now

This season Prasad did three things differently.

First, he got a soil test done before the season, so that his total nitrogen, phosphorus and potash were based on his own field rather than his uncle's habit. If you have a soil health card already, it is worth learning how to read it properly.

Second, he entered the transplanting date and variety for each field in the Mapis Farming crop cycle calendar. The calendar shows which growth stage each field should be at and what to watch for that week. When the expected panicle initiation week showed up in his Today list, he walked the field with a blade and split a dozen tillers. The tiny white tips were there.

Third, he split his nitrogen into rounds as the officer had advised, and noted each round in his field records with the date and the stage.

His field was not the darkest along the canal this year. He had not cut his fertiliser in total; he had only moved it to when the crop could use it. The planthoppers still came, but in smaller numbers, and he sprayed less. When the coastal winds blew in the last month, most of his crop stayed standing. His yield was a little better than the year before. He does not call it a miracle. He calls it paying attention.

If you are thinking of changing how you establish paddy too, read about direct-seeded rice and how it saves water.

Frequently asked questions

When should nitrogen be applied to paddy?

Nitrogen is usually applied in splits: a part at or soon after planting, a part during active tillering and a part around panicle initiation. The exact amounts depend on your soil test, variety and season. Follow your agriculture officer's or KVK's recommendation and time each round to the crop's stage, not to the calendar alone.

What is panicle initiation in rice?

Panicle initiation is the stage when the young panicle starts forming inside the main stem. It decides how many grains each panicle can carry, so nitrogen shortage at this point reduces yield. You can confirm it by slitting a main tiller near the base and looking for a tiny, fuzzy white tip.

What happens if I apply all the urea at once?

A single heavy dose is partly wasted because young plants cannot absorb it all. It also produces soft, crowded growth that attracts pests like brown planthopper and makes the crop more likely to lodge. Nitrogen also runs short later, at panicle initiation, when the crop needs it most.

How do I know if my paddy has too much nitrogen?

Very dark, droopy leaves, a dense canopy, many thin tillers, more pest and blast problems, and lodging near harvest are common signs. The crop may also mature later than nearby fields. If you see these, don't add more nitrogen and talk to your agriculture officer.

Can I use a leaf colour chart to decide fertiliser timing?

Yes. A leaf colour chart lets you compare the youngest fully opened leaf with standard shades to judge whether the crop needs nitrogen at that moment. Many agriculture offices and KVKs provide them and explain how to use them for your variety.