Crop management

• From a long–term experiment (started from 2010) on no tillage with the retention of previous crop residue i.e. conservation tillage (CT) under rice-maize system (previously rice-wheat system) found superior over the farmer’s tillage practice of conventional tillage without the crop residue (FT) in terms of :
  • grain yields of respective crops and their system yields,
  • soil nutrient status (soil organic matter, nitrogen, phosphorus and potassium),
  • cost of cultivation and hence net return, and
  • non-lodging plants
• Winter maize without tillage and rice residue anchored at 35 cm (3 Mt/ha dry weight) in the field followed by no tilled dry direct seeding of rice and maize residue anchored at 45 cm (2.0 Mt dry weight/ha) in the rice field (CT) found better in terms of yield, economics and soil health compared to farmers practice (FT).
• Conservation tillage in maize reduced the impact of drought by lowering soil temperature and surface evaporation, hence increased grain yield.
• In conservation tillage, Glyphosate as a broad spectrum herbicide (50% SL) sprayed @5ml/litre of water (i.e 600-700 litres of water/ha) at 10 -15 days before the crop planting reduced significantly the weed severity in maize.
• In case of conservation tillage in maize, Atrazine herbicide (pre-emergence) application of Atrazine (50%WP) @1.5 kg ai./ha within 24 hours of planting and in case of no tilled dry direct seeding of rice, Pendimethalin 30% EC @ 6ml/litre of water i.e 550 litres/ha within 48 hours of direct seeding found profitable.
• Irrespective of tillage methods, Nepalese hybrids (Rampur Hybrid-2 and RML-32/RML-17) produced the highest grain yield of maize in planting geometries of 60cm between rows and 25cm (66,666 plants/ha) between plants compared to the previously recommended spacing of 75cm X 25cm (53,333 plants/ha).
• In both the tillage methods, planting geometries of 60cm between rows and 25cm between plants for hybrids found suitable in Terai.
• In the mid hills under maize-tori system, conservation tillage surpassed farmers the practice of conventional tillage in terms of system yields and soil organic matter, N, P and K content.
• Under maize-wheat system, the tillage methods did not affect the grain and system yield for the two years of experimentation in Terai, but the net return was higher in conservation tillage over conventional tillage methods.
• Spring season maize can also be grown successfully without tillage operation.
• Tank mixture of Atrazine and Glyphosate (Atrazine @ 0.75kg a.i./ha + Glyphosate @2.5 ml/litre of water) or Atrazine (Atrazine @1.5kg a.i./ha as pre emergence ) + one hand weeding at 40 days after seeding during spring season maize found better for higher grain yield and net economic return in Terai, Nepal.
• Nitrogen application in 3 splits (10% at planting, 30% at five leaf stage, 30% at 10 leaf stage and 30% at tasseling resulted the significantly higher grain yield of maize.
• To enhance the profitability of maize based intercropping systems planting of three rows of soybean in between two rows of maize (100 cm between rows and 50 cm between plants with two plants per hill i.e 40, 000 maize plants/ha) proved beneficial over sole maize (53, 333/ha).
• Best time of planting for winter maize was last fortnight of Septembe and for spring it was mid February in uplands of Terai.
• For both tilled and no tilled condition, Chinese maize planter that drills the single seed per hill with 100% seed drilling efficiency found suitable for Terai and flat lands.