Cover Crops for Soil Health: 10 Best Options in Pakistan and South Asia
| Quick answer The best cover crops for soil health are sesbania, mung bean, cowpea, berseem, sorghum Sudan grass, sunn hemp, tillage radish, lentil, oats and phacelia. Legumes such as sesbania and sunn hemp fix 70 to 120 kg of nitrogen per acre. Grasses such as oats and sorghum Sudan grass build organic matter. Tillage radish breaks compacted subsoil. Sow one in any gap of 45 days or more, then plow it in three to four weeks before your main crop. |
Walk into two fields in the same village, on the same canal, with the same fertilizer bill. One bakes into a hard grey crust after the first irrigation. The other crumbles in your hand and holds moisture for days. The difference is rarely the fertilizer. It is almost always whether that soil has ever been covered and fed.
That is the whole job of a cover crop. You grow it not to sell, but to feed the ground under your feet. And it remains the cheapest reliable way to lift long term productivity on a South Asian farm. Over fifteen seasons of working with growers across Punjab and Sindh, the pattern is consistent: the fields that get a green manure crop once every rotation need less nitrogen, hold water better and recover faster from a bad year. This guide covers the 10 cover crops that actually perform in our climate, with real seed rates, nitrogen figures and timing, plus the soil and land calculators you can use to plan each one for your own acreage.
Key Takeaways
- Legumes give you nitrogen. Grasses and brassicas give you organic matter and structure. Most farms need both across a year.
- Sesbania is the single best all rounder for Pakistani conditions: 45 to 60 days, 80 to 120 kg of nitrogen per acre, and it loves heavy waterlogged ground.
- Timing beats species choice. Plow in while the crop is green, then wait three to four weeks before sowing your main crop.
- A 45 day gap between harvests is not wasted time. It is a free fertility window.
- Two cover crops mixed together usually outperform either one alone.
What Is a Cover Crop, and What Makes a Good One?
A cover crop is any plant grown to protect and improve soil rather than to harvest. When you turn it into the ground while it is still green, it is also called a green manure. Some cover crops, like mung bean, manage both jobs at once.
A good cover crop does at least two of the following:
- Fixes nitrogen: legume roots host rhizobia bacteria that pull nitrogen straight out of the air
- Adds organic matter: stems, leaves and roots decompose into the stable carbon that holds water and nutrients
- Keeps the surface covered: bare soil in June loses moisture fast and crusts hard
- Suppresses weeds: either by shading them out or by releasing natural compounds that block germination
- Breaks compaction: thick taproots and dense fibrous roots open channels no rotavator can reach
- Feeds soil biology: living roots release sugars that keep microbes and earthworms working
Organic matter is the number that ties all of this together. If you are not sure where your fields stand, run your figures through the soil organic matter calculator before you decide which cover crop to sow, and check your soil texture too, since sandy and clay soils reward very different species.
The 10 Best Cover Crops for Soil Health at a Glance
Here is the short version. Detailed profiles follow underneath.
| Cover crop | Type | Nitrogen fixed (kg per acre) | Seed rate (kg per acre) | Best window |
| Sesbania (Dhaincha) | Legume | 80 to 120 | 5 to 8 | May to June, Kharif gap |
| Mung bean | Legume | 30 to 50 | 6 to 8 | Kharif, doubles as cash crop |
| Cowpea (Lobia) | Legume | 40 to 80 | 8 to 10 | Hottest months, sandy soils |
| Berseem | Legume | 60 to 100 | 8 to 12 | October to March, Rabi |
| Sorghum Sudan grass | Grass | None | 8 to 12 | Warm season, degraded soils |
| Sunn hemp (Jantar) | Legume | 70 to 100 | 6 to 10 | Kharif gap, before vegetables |
| Tillage radish | Brassica | None | 3 to 5 | October to December |
| Lentil | Legume | 40 to 70 | 10 to 15 | October to March, before wheat |
| Oats (Jai) | Grass | None | 20 to 30 | October to December |
| Phacelia | Borage family | None | 3 to 5 | Cool season, before vegetables |
Seed rates shift with sowing method, seed size and soil condition, so treat these as a starting point and fine tune with the cover crop seeding rate calculator.
The 10 Best Cover Crops for Soil Health, Explained
1. Sesbania (Dhaincha): The Fastest Nitrogen Builder
If you only ever grow one cover crop, grow this one. Sesbania bispinosa is the most widely used green manure across Pakistan and India for good reason. It races to 1.5 or 2 metres in 45 to 60 days of summer heat, and it fixes 80 to 120 kg of nitrogen per acre while doing it.
It also handles the conditions that kill other cover crops. Waterlogged clay, salty patches, a field that sat flooded for a week: sesbania keeps going. Sow it in the gap after Rabi harvest, then plow it under six to eight weeks before you transplant rice or sow cotton.
- Nitrogen fixed: 80 to 120 kg per acre
- Days to plow in: 45 to 60 after germination
- Seed rate: 5 to 8 kg per acre
- Stands out for: waterlogged and heavy clay soils, mild salinity
Because sesbania supplies so much nitrogen, adjust the next crop accordingly. Work out what you can safely cut with the nitrogen balance calculator and the urea application rate calculator. Most growers find they can drop two to three bags of urea per acre.
2. Mung Bean (Green Gram): The One That Pays You Twice
Mung bean is the practical choice for anyone who cannot afford to leave a field earning nothing. Harvest the pods, sell them, and the residue still leaves nitrogen and organic matter behind. Or skip the harvest, cut it at 45 days before flowering, and turn the whole plant in as pure green manure.
It fixes 30 to 50 kg of nitrogen per acre. That is less than sesbania, but you are getting a saleable crop out of the same 60 days.
- Nitrogen fixed: 30 to 50 kg per acre
- Seed rate: 6 to 8 kg per acre
- Duration: 60 to 70 days to maturity, or incorporate at 45 days
- Stands out for: sandy loam and loam soils in Kharif, and for cash flow
Not sure whether to sell it or plow it in? Put both scenarios side by side in the crop profit comparison calculator and let the numbers decide.
3. Cowpea (Lobia): The Heat Proof Ground Cover
When the thermometer sits above 40 degrees and nothing else wants to grow, cowpea does. It sprawls flat across the ground, smothering weeds under a dense mat, and it shrugs off both heat and moderate drought.
The vines are soft and watery, so they break down quickly once turned in. Nitrogen from a cowpea crop reaches your next crop faster than nitrogen from a woody stemmed green manure.
- Nitrogen fixed: 40 to 80 kg per acre
- Seed rate: 8 to 10 kg per acre
- Tolerance: high heat, moderate drought
- Stands out for: sandy soils and brutal summer gap periods
4. Berseem (Egyptian Clover): Fodder Income Plus Soil Repair
Half the country already grows berseem for fodder, which makes it the easiest cover crop to adopt. You are not changing your system, you are just changing what happens at the end of the season.
Take your cuts for animal feed through winter as usual. Then, instead of clearing the field, plow the final regrowth into the soil before your summer crop. Across the whole season a berseem crop can leave 60 to 100 kg of nitrogen per acre behind along with a serious volume of root mass.
- Nitrogen fixed: 60 to 100 kg per acre across the season
- Seed rate: 8 to 12 kg per acre
- Season: October to March, Rabi
- Stands out for: farms with livestock, since you get feed and fertility from one sowing
To plan cuts and yields properly, the fodder production calculator will tell you how much green matter each acre should give you before the final incorporation.
5. Sorghum Sudan Grass: The Biomass Machine
This one fixes no nitrogen at all. Grow it anyway when your problem is dead, compacted, organic matter poor soil, because nothing else produces bulk like it. Three to five tonnes of dry matter per acre is normal, and the root system goes down 1.5 metres.
Those roots are the real prize. They punch through hardpan, and when they rot they leave behind a network of channels that water and air follow for years afterwards. Mow it once at about a metre tall to force even deeper rooting, then incorporate the regrowth.
- Biomass: 3 to 5 tonnes dry matter per acre
- Seed rate: 8 to 12 kg per acre
- Root depth: up to 1.5 metres
- Stands out for: rebuilding degraded and hardpan affected fields
Estimate what all that material is actually worth to your soil with the green manure biomass calculator.
6. Sunn Hemp (Jantar): The Nematode Fighter
Sunn hemp deserves far more attention than it gets. It grows fast even in poor soil, fixes 70 to 100 kg of nitrogen per acre, and it does something no other cover crop on this list does as well: it suppresses root knot nematodes.
That makes it the obvious choice before tomato, brinjal and potato, the three crops most often wrecked by Meloidogyne. If a block of your land has a nematode history, put sunn hemp through it in the Kharif gap.
- Nitrogen fixed: 70 to 100 kg per acre
- Nematode effect: good suppression of Meloidogyne root knot species
- Seed rate: 6 to 10 kg per acre
- Stands out for: vegetable rotations and nematode infested blocks
7. Tillage Radish (Daikon): The Biological Plow
Radish is grown as a cover crop for one reason: the taproot. It drills 40 to 60 cm straight down through compacted subsoil, and when the plant dies back in winter cold or gets incorporated, it leaves a vertical tunnel behind.
Multiply that by thousands of plants per acre and you have drainage improvement no tractor pass can match. It fixes no nitrogen, but it scavenges nutrients from deep in the profile and brings them back to the surface as it decomposes.
- Root depth: 40 to 60 cm
- Seed rate: 3 to 5 kg per acre
- Season: late Rabi, October to December
- Stands out for: compacted clay and loam that waterlogs after irrigation
Before you commit, check how bad your problem actually is using the soil compaction risk estimator. Fields scoring high are exactly where radish earns its keep.
8. Lentil: The Quiet Pre Wheat Advantage
Lentil is mostly grown as a Rabi cash crop, and it does that job well. What gets overlooked is what it leaves behind. Fine roots improve structure, residues break down quickly, and 40 to 70 kg of nitrogen per acre stays in the field.
Slot lentil in ahead of wheat and you can usually cut the nitrogen fertilizer on that wheat crop by 20 to 30 percent with no yield penalty. On marginal dryland, that saving matters more than almost anything else you can do.
- Nitrogen fixed: 40 to 70 kg per acre
- Seed rate: 10 to 15 kg per acre
- Season: October to March
- Stands out for: pre wheat rotations in dryland and marginal areas
Map out where lentil fits across your fields with the crop rotation planner.
9. Oats (Jai): The Weed Suppressor
Oats grow fast in cool weather and throw up a canopy dense enough to shut weeds down before they establish. Oat roots also release compounds that block germination in several common weed species, which is a real advantage in fields with a bad seed bank.
The straw is high in carbon, so it decomposes slowly. That is a feature, not a fault. Slow decomposition is what builds stable organic matter rather than a quick nutrient flush.
- Biomass: 2 to 3 tonnes dry matter per acre
- Seed rate: 20 to 30 kg per acre
- Season: October to December
- Stands out for: weed control and carbon building in Rabi
Because oat straw is carbon rich, give it extra decomposition time or pair it with a legume. The carbon to nitrogen ratio calculator shows you why that balance matters.
10. Phacelia: The Pollinator Magnet
Phacelia is still rare in Pakistan but it is worth trialling on a small block, especially if you grow vegetables. It covers ground quickly, and its purple flowers pull in bees and beneficial insects in numbers that surprise most first time growers.
The tissue is soft and non fibrous, so it releases nutrients within two to four weeks of incorporation. For a market garden turning beds over quickly, that speed is exactly what you want.
- Decomposition: very fast, nutrients released in two to four weeks
- Pollinator value: outstanding, attracts bees and predatory insects
- Seed rate: 3 to 5 kg per acre
- Stands out for: market gardens and tunnel houses ahead of vegetables
How Do You Choose the Right Cover Crop for Your Farm?
Match the crop to three things: the gap in your calendar, your soil type, and the problem you most want fixed. Find your row in the table below.
| Your situation | Best choice | Why it works |
| Empty field in May and June | Sesbania, cowpea or sunn hemp | They thrive in extreme heat and fix nitrogen fast |
| Empty field in October and November | Oats, berseem or radish | Cool season growth holds the soil through winter |
| Heavy clay that seals and cracks | Sesbania, tillage radish or sorghum Sudan | Strong roots open the profile and improve drainage |
| Sandy soil losing nutrients | Cowpea or mung bean | Quick cover plus nitrogen and fast decomposing residue |
| Before tomato, brinjal or potato | Sunn hemp | Suppresses root knot nematodes as well as weeds |
| You need fodder income too | Berseem, cowpea or oats | Cut or graze first, then plow the regrowth in |
| Weeds are your main problem | Oats or sorghum Sudan grass | Dense canopy plus natural growth inhibiting compounds |
| You want the next crop fed fast | Phacelia or mung bean | Soft tissue breaks down in two to four weeks |
Fitting a cover crop into a tight rotation is the part most people get wrong. Sketch the dates first with the crop calendar generator and the planting date and maturity calculator, and you will quickly see whether a 45 day window is really there.
How Do You Incorporate a Cover Crop Correctly?
Timing decides whether a cover crop feeds your next crop or starves it. Follow these five steps.
- Plow it in while it is still green. Green tissue is high in nitrogen and low in fibre, so it breaks down fast. Once the stems go woody, decomposition slows sharply.
- Chop and mix into the top layer. Use a rotavator or disc harrow and work the material into the top 15 to 20 cm. Burying it deeper slows decomposition because oxygen is scarce down there.
- Irrigate straight afterwards. Moisture is what microbes need to get to work. A dry field just holds intact plant material for weeks.
- Wait three to four weeks before sowing. This is the step people skip. Fresh residue makes soil bacteria pull nitrogen out of the soil to break it down, so a crop sown too early can go pale and stunted even though plenty of nitrogen is technically present.
- Cut your fertilizer plan accordingly. Recalculate before you buy, not after. Growers who forget this step pay twice for the same nitrogen.
For the irrigation after incorporation, the crop water requirement calculator helps you apply enough to trigger decomposition without waterlogging the field.
Five Mistakes That Waste a Good Cover Crop
These are the failures I see most often, and every one of them is avoidable.
- Sowing too late. A cover crop with only 25 days of growth left produces almost nothing. If the gap is that short, skip it and plan better next season.
- Letting it flower and set seed. Nitrogen moves into the seed and the stems turn woody. You also risk it volunteering as a weed in your next crop.
- Sowing at half rate to save on seed. Thin stands let weeds through and cut biomass by more than the seed saving is worth. Use a proper seed rate calculator instead of guessing.
- Ignoring phosphorus. Legumes fix their own nitrogen but they cannot nodulate well without phosphorus. A half bag of single super phosphate per acre is usually all it takes. Check the numbers with the phosphorus application calculator.
- Expecting results in one season. Weed pressure and crusting improve immediately. Organic matter is a three to five year project.
What Does a Cover Crop Cost, and What Do You Save?
The economics are the easiest part of this argument. Seed is the only meaningful cash cost, and the nitrogen alone usually pays it back within one season.
| Item | Typical range per acre | What you get back |
| Sesbania seed | 5 to 8 kg | 80 to 120 kg nitrogen, worth 2 to 3 bags of urea |
| Land preparation and sowing | One light pass | A crop that needs almost no care for 50 days |
| One or two irrigations | 2 to 3 acre inches | Two tonnes or more of fresh biomass |
| Starter phosphorus (optional) | Half bag SSP | Faster nodulation and stronger nitrogen fixing |
| Total cash outlay | Low, mostly seed | Better structure, fewer weeds, higher yields ahead |
Run your own version of this with the crop cost of production calculator, and convert between acres, kanals and hectares using the land area converter if your land records use mixed units.
Cover crops also stack well with other organic inputs. Many growers pair a green manure with vermicompost or a biofertilizer application programme, and use surface residue as mulch rather than incorporating all of it.
Frequently Asked Questions
Do cover crops replace fertilizer completely?
No, but they replace a large part of your nitrogen. A strong sesbania or berseem crop supplies 60 to 90 kg of urea equivalent per acre. Phosphorus, potassium and micronutrients still need to be checked against a soil test and topped up.
How long does a cover crop need to grow before I plow it in?
Most legumes give you the best return between 45 and 60 days, plowed in while they are still green and before the stems turn woody. Wait too long and the material becomes high in carbon, which slows nitrogen release.
Can I graze animals on cover crops?
Yes. Berseem, cowpea and oats all take grazing or cutting well. Leave at least a third of the growth and the whole root system, and you still get most of the soil benefit while feeding your animals.
Do cover crops need fertilizer of their own?
Very little. Legumes make their own nitrogen once nodules form. A half bag of single super phosphate per acre helps nodules develop faster, and sandy soils sometimes respond to a small potassium dose.
Will a cover crop use up water my main crop needs?
It uses some, but it also improves infiltration and cuts evaporation from bare soil, so the balance usually works in your favour. In very dry years, choose cowpea or lentil rather than a tall grass, and plow in earlier.
Which cover crop is best for a small farm of one or two acres?
Mung bean, because it pays twice. You harvest a saleable crop and still leave nitrogen rich residue behind. Sesbania is the better pick if your only goal is rebuilding tired soil quickly.
Can I mix two cover crops together?
Mixing is often better than a single species. A legume with a grass, such as cowpea with sorghum Sudan grass or berseem with oats, gives you nitrogen and bulk carbon at the same time. Sow each at roughly 60 percent of its solo rate.
How soon will I see a difference in my soil?
Weed pressure and surface crusting improve in the first season. Measurable gains in organic matter take three to five years of steady use, which is why one cover crop every rotation beats one heroic effort.
If a soil test has already flagged a problem, cross check it against the soil nutrient deficiency checker and the potash application calculator before you assume a cover crop will fix everything.
The Bottom Line
Cover crops for soil health are the highest return, lowest risk investment available to most farmers in this region. The seed is cheap, the labour is minimal, and the soil you build keeps paying out season after season with less bought nitrogen and steadier yields in bad years.
Do not try to redesign your whole rotation at once. Pick one gap in your calendar, sow one suitable species, and see what the next crop does. Sesbania in the Kharif gap or berseem through Rabi is the easiest place to start.
Ready to plan it properly? Start with the cover crop seeding rate calculator to work out your seed order, then browse the organic farming calculators and the crop guides library for the crop you are planting next. The full Foods Farming calculator collection covers soil, irrigation, fertilizer and farm finance in one place.