V.K. Choudhary

Crop and water productivity, profitability and energy consumption pattern of a maize-based crop sequence in the North Eastern Himalayan Region, India

Mono-cropping is the most common farming practice followed in the North Eastern Hilly Region (NEHR) of India and farmers leave the land fallow after harvesting the main crop. The identification of suitable sequential crops is essential to increase the cropping intensity, land-use efficiency and overall productivity of the land. Therefore, a study was carried out during 2008–09, 2009–10 and 2010–11 on maize (rainy season) followed by table pea, mustard, French bean and groundnut (post rainy season). Sequence crops were imposed with paddy straw mulch at 5.0 t ha−1 and without mulch. The availability of water and moisture retention was higher (p < 0.05) on mulched plots, yield was also higher. However, recorded soil temperature was higher on mulched plots at 08.00 hours and lower at 12.00 and 16.00 hours compared with the no-mulch plots. Recorded maize equivalent yield, production efficiency, economics and total energy use and output (MJ ha−1) were higher for maize–French bean.

Tillage and mulch effects on productivity and water use of pea and soil carbon stocks

Soil management can notably influence crop production under rainfed farming; however, improper soil management is one of the key factors threatening sustainability. The objective of this 3 years’ study was to evaluate the performance of two types of tillage: conventional tillage (CT) and zero tillage (ZT) systems with four mulches; paddy straw mulch (PSM), maize stubble (MS), Imperata cylendrica (thatch grass, TG) and no mulch (NM) on yield and water use of pea (Pisum sativum) and physico-chemical properties of soil. CT and PSM have registered 11.1% and 36.1% higher pod yield, 10.0% and 40% improvement of water use efficiency (WUE) and 9.7% and 49.2% better harvest monetary benefit (HMB) over ZT and NM, respectively. Soil moisture content (SMC) was higher with ZT than CT. Placement of mulch has considerably higher SMC on upper soil layer over NM, but at deeper depth, there was no such evidence. The soil organic carbon (SOC) was considerably improved by 4.1% with ZT than CT, whereas, MS improved SOC by 1.9% than NM. The findings clearly suggested that CT along with PSM registered improvement in pod yield, WUE and HMB, but ZT and MS improved SOC at different soil depths and responded to carbon stock management.

Nodulation Productivity and Nutrient Uptake of Cowpea (Vigna unguiculata L. Walp) with Phosphorus and Potassium under Rainfed Conditions

Low availability of phosphorus (P) and potassium (K) in acidic soil is a major constraint for crop production. Therefore, a field study was conducted to determine the effects of K and P on nodulation, productivity, and nutrient uptake of cowpea (Vigna unguiculata L. Walp) under rainfed conditions. The K and P were subjected to main and subplots, respectively with 100, 75, and 50% of fertilizer application. The growth and yield attributes were better using 100% K with 100% P. However, 100% K resulted in 20.9 and 16.9% greater green pod and stover yield than 50% K. Similarly, 100% P recorded 20.2 and 15.6% greater green pod and stover yield than 50% P. Uptake of nutrients such as nitrogen (N), P, and K followed the trend of greater to lower, 100% > 75% > 50%, in order for K and P. Similarly, nutrient-use efficiencies and production efficiency followed the trend of nutrient uptake.

Herbicide weed management on weed dynamics, crop growth and yield in direct-seeded rice

Effect of herbicide combinations were evaluated in Raipur (Chhattisgarh) on crop growth, weed suppression and rice yield in direct-seeded rice (DSR) system during 2014 and 2015. Results revealed that combination of pyrazosulfuron + pretilachlor provided wide spectrum weed control at 15 + 600 g/ha to 30 + 1200 g/ha (61.6 -81.5%), which was comparable to two hand weeding at 15 and 30 days after sowing. Weed control efficiency was recorded to the tune of 40.0 - 89.9%, with highest in two hand weeding (84.6 -89.9%) and lowest in pendimethalin and lowest dose of pyrazosulfuron + pretilachlor in 2014 (40.0%) and pyrazosulfuron alone in 2015 (48.5%). The crop growth parameters (tillers, total dry matter/hill and leaf area index), yield attributes (panicle length, panicle weight, filled grains/panicle) and grain yield were recorded highest in two hand weeding (2.69 t/ha in 2014 and 5.87 t/ha in 2015) followed by pyrazosulfuron + pretilachlor at 15 + 600, 16.88 + 675 and 30 + 1200 g/ha. However, the least rice grain yield was recorded under weedy plot (1.45 t/ha in 2014 and 2.17 t/ha in 2015). The results suggested that pyrazosulfuron + pretilachlor at 15 + 600, 16.88 + 675 and 30 + 1200 g/ha were the best broad spectrum effective herbicide in order to minimize the diverse weed flora in DSR system.

Evaluation of different rootstocks on the performance of some mandarin cultivars under mid hill conditions of Arunachal Pradesh

Four rootstocks, viz., C. latipes, Volkamariana, Tanyum (C. medica) and rough lemon (C. jambhiri) were used for budding different genotypes, viz., Hill mandarin, Nagpur mandarin, Khasi mandarin and Sikkim mandarin as a scion cultivars. Plant height was observed higher with Nagpur mandarin followed by Hill mandarin. Among the rootstocks, TCSA was noticed higher with C. latipes (49.31). Sikkim mandarin recorded the highest canopy spread in both the directions with different rootstock combinations. Flower and fruit drop percentage was recorded least in Khasi mandarin (25.18 and 6.20, respectively). Fruits/plant was recorded more in Khasi mandarin (399.47) followed by Sikkim mandarin (345.42). Nagpur mandarin and Tanyum recorded the higher peel weight (33.46; 32.99) and thickness (5.37; 5.04) among scion and rootstock, respectively. Fruit weight and juice content was recorded more in Khasi mandarin (143.09; 76.57, respectively). Highest seed number was recorded with tanyum (13.67). C. volkamariana positively influenced the TSS content of fruits. Plants of Volkamariana came to early harvesting, i.e. in the first week of November, whereas on rough lemon it was late, i.e. last week of December to first week of January. Our study showed that C. volkamariana was found to be the best rootstock for Khasi mandarin in Arunachal Pradesh.

Amelioration of Acidic Soil and Production Performance of Cowpea by the Application of Different Organic Manures in Eastern Himalayan Region, India

Acidic soils are limiting the production potential of the crops because of low availability of basic ions and excess of hydrogen (H+), aluminium (Al3+), and manganese (Mn2+) in exchangeable forms. Therefore, a field study was conducted to know the ameliorating effect of organic manures on acidic soils and production performance of cowpea (Vigna unguiculata L., Walp.) by using different locally available organic manures. Growth and yield attributes were observed to be significantly greater with vermicompost (VC) followed by poultry manure (PM). Porosity, maximum water-holding capacity (MWHC), and organic carbon were greater with farmyard manure (FYM) and cow dung manure (CDM). However, water retention at field capacity (FC), permanent wilting point (PWP), bulk density (BD), pH, and availability of nitrogen (N), phosphorus (P), and potassium (K) were greater with VC. However, physical and chemical properties were deteriorated in control plots.