Distinguishing N vs S deficiency by leaf yellowing pattern, old vs new leaves, mobile nutrient.
How do I tell nitrogen deficiency from sulphur deficiency just by looking at leaves?
AAnil Kushwaha8mo ago · 221 views
6 Answers
🌾Farmer.in Krishi TeamExpert ✓8mo ago
The quickest field clue is which leaves yellow first. Nitrogen is mobile in the plant, so the plant moves it from old to new leaves and the lower, older leaves yellow first, often starting from the leaf tip down the midrib. Sulphur is not mobile, so the younger, upper leaves yellow first while lower leaves stay greener. Nitrogen deficient plants are also generally stunted and pale all over in severe cases, while sulphur deficiency in mustard and pulses gives uniform pale young leaves and sometimes cupping. Because both can look similar early, confirm with a soil or tissue test before deciding. Correct nitrogen with split urea and sulphur with gypsum, bentonite sulphur, or SSP, adjusting to your Soil Health Card and KVK; do not over apply.
HHoshiyar Singh8mo ago
In my mustard the new top leaves went pale while the bottom stayed green, and it was sulphur. The trick the expert mentioned about top leaves versus bottom leaves is exactly what told me apart from nitrogen. Gypsum at sowing fixed it the next season.
DDalbir Singh7mo ago
Before you decide it is a nutrient, rule out water problems. My wheat went yellow all over and I almost sprayed urea, but it was waterlogging from a blocked drain choking the roots. Once the water drained the colour came back on its own. Yellow leaves do not always mean a missing nutrient.
KKishan Lal Yadav7mo ago
If you grow a lot of pulses and oilseeds, keep sulphur in mind from the start instead of waiting for yellow leaves. Those crops are heavy sulphur feeders. I now use SSP as my phosphorus source for mustard so the sulphur comes along with it, and I rarely see that pale top growth anymore.
PPhool Singh Rana6mo ago
In my chana the lower leaves yellowed first and it was nitrogen, exactly the old leaf clue the team gave. A small urea top dressing with irrigation greened it. Knowing old versus new leaves saved me from spraying the wrong thing.
OOmprakash Yadav6mo ago
Do not just trust the leaf colour, get a soil or tissue test if you can before spending on the wrong input. I was sure mine was sulphur and almost bought gypsum, but the test showed nitrogen was the real shortfall. The leaf clue points you, the test confirms it.