Higher Maize Grain Yield Research Articles

English

In Nigeria and other Sub-Saharan Countries of Africa, erosion is pervasive and major source for loss of soil and productivity. This has necessitated continued search for appropriate soil management technologies to ensure sustained and profitable crop production. An experiment was carried out using maize (Zea mays L.) to evaluate organic carbon dynamics and changes in some physical properties of soil and grain yield of maize under conservative tillage practices on an ultisol in Southeastern Nigeria. The study consisted of three conservative tillage practices which were laid out in the field using randomized complete block design replicated seven times. Data were analyzed using statistical analysis for agricultural science. Results showed that tillage reduced seedlings emergence by 5 days compared to zero tillage. Highest grain yield of maize, significantly higher by 4 and 20% was obtained in deep tilled plot when compared to yields in shallow and zero tilled plots. Deep tilled plot had 2-9% significantly lower bulk density and 20-36, 1-8 and 27-55% higher total porosity, gravimetric moisture content and saturated hydraulic conductivity when compared to shallow tilled and zero tilled plots. Deep tilled plot had 15 and 55% significantly organic carbon when compared to their counterparts in shallow and zero tilled plots. Conservative tillage practices are recommended for sustainable and profitable production of maize crop in Nigeria. Key words: Edaphic, grain yield, organic carbon, soil properties, tillage practices.

Intercropping System of Maize with Different Winter Vegetables

The experiment was conducted at farmers’ fields of Hqripur in Dauadkandiupzilla underOn- Farm Research Division of Bangladesh Agricultural Research Institute, Comilla during the rabi seasons of 2012-13 and 2013-14 toevaluate the performance of maizeunder intercropping with different winter vegetables. The experiment comprised of four treatments viz., Maize + Spinach, Maize + Red amaranth, Maize + Coriander and Sole maize with four replications. Results revealed that each of maize- vegetables intercropping combinations showed superior in terms of gross return,net return, BCR and Maize equivalent yield (MEY) over sole cropping of maize. The highest grain yield of maize (9.61 t ha-1) was obtained fromMaize + coriander due to the highest contribution of yield contributing characters and lowest (7.8 t ha-1) yield was received from the treatment of maize + red amaranth intercropping system, where the sole maize produced second highest yield.The highest Maize equivalent yield (12.85 t ha-1), gross return (Tk. 128500 ha-1), net return (Tk. 80080 ha-1) and BCR (2.65) were found in the intercropping system Maize + Spinach which indicated the advantage of intercropping over the sole Maize cropping.

Evaluating the Impact of Different Tillage Regimes and Nitrogen Levels on Yield and Yield Components of Maize (<i>Zea mays</i> L.)

A field study to evaluate the impact of different tillage regimes and nitrogen levels on yield and yield components of maize (Zea mays L.), was conducted during autumn 2014 at Students Farm, Department of Agronomy, University of Agriculture, Faisalabad. The experiment was laid out in RCBD (Randomized Complete Block Design), with split plot arrangement having three replications. The experiment was comprised of three tillage regimes (Minimum, Conventional and Deep) and three nitrogen levels viz: 100, 200 and 300 kg•ha-1. Urea was used as a source of nitrogen, sulphate of potash as a source of potassium and triple super phosphate as a source of phosphorous. The amount of phosphorous and potash was constant in all the treatments i.e. 125 kg•ha-1 and 100 kg•ha-1 respectively. Results of present study are summarized as yield parameters are significantly affected by different nitrogen levels and tillage regimes. Maximum number of plants at harvest (7.93), number of grain rows per cob (17.70), number of grains per row (34.31), number of grains per cob (678.58), and cob weight (187.50 g) were observed in deep tillage at 200 kg•ha-1 nitrogen application. 1000-grain weight (275.52 g), biological yield (15.66 t•ha-1), grain yield (6.16 t•ha-1) and dried stalk yield (9.91 t•ha-1) were observed maximum in deep tillage at 200 kg•ha-1 nitrogen application. Harvest index significantly affected by tillage regimes and maximum harvest index (39.58%) were recorded in deep tillage which was statistically at par with conventional tillage (38.83%). It was concluded that higher grain yield of maize can be obtained by deep tillage with the application of 200 kg•ha-1 nitrogen application under the prevailing conditions of Faisalabad.

Yields and Yield Components of Maize (Zea Mays L.) and Soybean (Glycine Max) as Affected by Different Tillage Methods

Abstract At the experiment station of the Krizevci College of Agriculture, yield and yield components of maize (Zea mays L.) and soybean (Glycine max) grown in rotation under five different methods of tillage were investigated. The aim of this study was to determine the effect of different tillage methods on yield and yield components of maize and soybean. The results and the determined number of plants per hectare of maize and soybean show that more favorable conditions for germination are in variants where ploughing performed in the autumn (variants C, D and E). During a four-year study, the minimum number of plants per hectare of maize and soybean was found in variant A. The dry season in panicle stage of maize in 2006 has lowered yields compared to 2008, and the drought in 2007 during the seed-filling period reduced the yield and the 1000 kernel weight of soybean compared with 2009 in all variants of tillage methods. The highest grain yield of maize was recorded in variant B. During 2006, with the unfavorable weather conditions, the lowest grain yield of maize was recorded in variant E with intensive tillage treatment. The highest yield of soybean was recorded in variant E, but there were no statistically significant differences compared to variants with the reduction of additional tillage interventions (variant B, C and D). With respect to maize grain and soybean seed yield, variant A was the lowest. Considering the achieved yields of maize grain, there is a possibility of reducing additional tillage interventions, whilst for achieving higher yield of soybean seed intensive tillage is recommended.

Intercropping Maize with Different Vegetables

An intercropping experiment was conducted in the farmer’s field at Farming Systems Research and Development (FSRD) Site, Kushumhati, Sherpur in sandy loam soil of medium high land during rabi season 2011-12 to observe the productivity and economic feasibility of intercropping systems as compare3d to sole crop (viz. maize + potato, maize + Radish, maize-+-coriander, maize + bushbean, maize + spinach, maize + lalshak and maize sole). The result indicated that grain yield of maize was reduced due to intercropping systems but this reduction was compensated by intercropped. The highest grain yield of maize was found from sole maize (10.90 t ha-1) and lowest (9.32 t ha-1) from intercropped with potato. The maximum maize equivalent yield (14.04 t ha-1), gross return (Tk.10,5300/ha),gross margin (Tk. 75,527/ ha),, and benefit cost ratio (BCR) (3.54) was obtained from maize + bushbean intercropping systems which was adventitious over sole maize cropping.Bangladesh Agron. J. 2015, 18(1): 49-52

Yield Response of Maize to Integrated Soil Fertility Management on Acidic Nitosol of Southwestern Ethiopia

A B S T R A C T Poor crop productivity, high cost of inorganic fertilizers and low crop response to inorganic fertilizers are major problems that affect sustainability of crop production in Southwestern Ethiopia. Application of inorganic fertilizers at rates much below the recommendation, which is mainly due to the limited economic capacity of smallholder farmers, has become the underlying cause of poor crop productivity along with the worsening soil acidity condition in the region. Hence, the effect of integrated soil fertility management on the productivity of maize was investigated on acidic nitosols of the region as a cheaper and sustainable alternative to the sole application of inorganic fertilizers. Different proportions of inorganic fertilizers, compost and Tithonia biomass were therefore tested on-farm using RCB design. Grain yield of maize (kg haG 1 ) was significantly affected by soil fertility management practices (p<0.05). Data collected in 2010 indicated that 50% recommended NP and 50% compost gave the highest grain yield of maize (4360 kg haG 1 ) compared to the control which gave the lowest yield (1920 kg haG 1 ). Similar yield response pattern was also observed in 2011. Integrated use of inorganic fertilizers and organic sources of plant nutrients has therefore, shown remarkable potential for efficient nutrient supply in maize based cropping systems on acidic nitosols of Southwestern Ethiopia. However, the potential role of various organic materials including Tithonia to ameliorate soil acidity or mitigate its effects on crop productivity need to be further investigated.

Productivity enhancement and biofortification of maize (Zea mays)- wheat (Triticum aestivum) cropping system through integrated potassium management

A field experiment was conducted during the kharif and rabi seasons of 2010-11 and 2011-12 at Indian Agriculture Research Institute, New Delhi to find out the performance of maize (Zea mays L.) - wheat (Triticum aestvum L.) cropping system with integrated potassium management through muriate of potash and farmyard manure. The experiment was laid out in randomized block design consisted of ten treatments and replicated thrice. Results revealed that all the treatment with potassium irrespective of sources significantly increased grain yield and nutrient concentration in grain of maize and wheat. The application of 60 kg K through muriate of potash + 30 kg K through farmyard manure resulted into highest grain yield of maize (4.44 and 5.42 tonnes/ ha) and wheat (5.39 and 5.49 tonnes/ ha). All treatment applied with farmyard manure shows higher macro – micro nutrient concentration in grain over control. The application of 60 kg potassium supplemented as 30 kg K through MOP and 30 kg K through farmyard manure in maize and application of 60 kg K through MOP alone in wheat resulted into highest system productivity (7.82 and 8.81 tonnes/ha).

Nitrogen (N) and Phosphorus (P) Fertilizer Application on Maize (Zea mays L.) Growth and Yield at Ado-Ekiti, South-West, Nigeria

Nutrient depletion as a result of continuous cultivation without supplementary addition of external inputs is a major challenge to agricultural productivity in South-west Nigeria. An experiment was set up to evaluate the effects of nitrogen (N) and phosphorus (P) fertilizer application rates on the performance of maize (Zea mays L.) in field trials at the Teaching and Research Farm, Ekiti State University, Ado-Ekiti, south-west Nigeria. The treatments consisted of 2 factors (i) N at 0, 30, 60, 90kg N.ha -1 (ii) P at 0, 15, 30, 45kg P∙ha -1 in all possible combinations and laid out in a randomized complete block design arranged with three replicates. Data of plant height, leaf area, stem girth and cob length, cob diameter, 100 grain weight and grain yield were collected. The result showed that plant height, stem girth and leaf area∙ plant -1 increased with N and P fertilizer rates. Cob length, cob diameter, 100 grain weight and grain yield, significantly (P=.05) increased with N and P application such that 90kg N∙ha -1 and 30kg N∙ha -1 gave the highest values. It may be concluded that application of the combination of N at 90kg∙ha -1 and P at 30kg∙ha -1 which produced the highest grain yield of maize could be regarded as the optimum for N and P in the study area. Therefore, further work should be carried out to ascertain the validity of this rate for maximum productivity. Original Research Article Olusegun; AJEA, 6(1): 22-29, 2015; Article no.AJEA.2015.061 23

Influence of stabilized nitrogen fertilizer use on yield, nutrient uptake and soil quality under maize-wheat sequence in Uttar Pradesh

Field experiments were conducted to study the impact of stabilized N fertilizer on yield, nutrient uptake and soil quality under maize-wheat cropping sequence at Fertilizer Research Farm, Uttaripura, Kanpur Nagar (U. P.), Chandra Shekhar Azad University of Agriculture & Technology, Kanpur during 2010–11 and 2011–12. Results indicated that grain and straw yield of maize-wheat significantly increased with the use of different urea A Lab over (T1) urea lab 8041 (plain urea). Significant increase in yield of maize-wheat was also noted within each urea A Lab up to urea A Lab 8044. The highest grain yield of maize and wheat was noted 33.15 and 56.75 q/ha, respectively, with urea A Lab 8045 (T6). The per cent response in grain of maize-wheat at T6 over T2 was noted (6.75 and 10.25 q/ha) with corresponding per cent response 25.56 and 22.04, respectively. Nutrient uptake (NPK) also significantly increased with various urea A Lab over urea Lab (T2). Protein content in both maize and wheat positively responded with the use of different urea A Lab over urea Lab. The response of various urea A Lab 100% was almost at par with 125% urea Lab 8046 (plain urea).

Effect of certain pesticides alternative against Sesamia cretica (led.) And Ostrinia nubilalis (hub). In maize fields. Beni- Suef Governorate.

Two experiments were conducted in maize fields in Beni Suef Governorate to evaluate some insecticides alternatives to control the pink stem borer, Sesamia cretica and European corn borer, Ostrinia nubilalis at an early planting date during April and late planting date at the end of May. The results showed , The plant extract Tagetes oil was the most effective against the pink corn borer, followed by the algal metabolite C (the algal metabolites of Chlorella vulgaris) as a compared with the stander biocide Spintor 24% . The average percentage reduction of perforated leaf plants and dead heart plants were (86.53 & 79.50), (61.95 & 54.23) and (89.56& 91.07 %) for early planting date and were (81.11 & 78.33), (46.67& 63.33) and (86.67 & 80.71 %) for late planting date, respectively. Concerning on the efficiency of these treatments on the infestation of European corn borer, O. nubilalis. The plant extract Tagetes oil was the most effective followed by the algal metabolite C as a compared with the stander biocide Spintor 24%. The seasonal average percentage reduction of tunnel holes and diapouse larvae were (69.66 & 55.26), (49.48 & 34.82) compared with (76.34 & 67.76 %) for stander biocide Spintor 24% and were (73.47 & 53.90), (52.68 & 41.74) compared with (76.59 & 63.15 %) for stander biocide Spintor 24% at an early and late planting date, respectively. The algal metabolite A (the algal metabolites of Apanocapsa pulchra) was the least effective against S. cretica and O. nubilalis followed by B (the algal metabolites of Aphanocapsa elachista) as a compared with the stander biocide Spintor 24%. On the other hand, the effect of these treatments on the actual yield were studied. The plant extract Tagetes oil and the stander biocide Spintor 24% gave the highest grain yield of maize in the early and late plantations. The average actual yield were (19.28, 16.89) and (22.19, 17.74) ardab / feddan indicating an increase of (33.27, 39.27%) and (42.02, 42.18 %) than control for early and late planting date, respectively.

Response of Maize Crop to Spatial Arrangement and Staggered Interseeding of Haricot Bean

Field studies conducted to determine the effects of intercrop row arrangements and staggered intercropping of haricot bean (Phaseolus vulgaris L.) on the performances of maize (Zea mays L.) crop at Hallaba and Taba areas in 2013 cropping season, southern Ethiopia, revealed that there were significant effects of cropping patterns and staggered interseeding of the legume component on growth and yield components of maize crop. Significant interaction of row arrangement × intercropping time of haricot bean was observed with respect to leaf area index (LAI) of the maize crop. Increasing trends of LAI of maize crop were observed as interseeding of haricot bean was delayed for 3 weeks after maize (WAM) that stabilized during the 6 WAM interseeding time. Maize stover production was significantly high at 1:2 row ratio and delaying of the undersowing haricot bean in the already established maize crop for 6 weeks, 10.94 tha-1 and 11.39 t ha-1, respectively. Maize grain yield showed a significant variation with respect to the staggered sowing of haricot bean, whereby the highest (3.99 t ha-1) being recorded when haricot bean intercropping was delayed for 21 days after maize planting. The data of this study revealed that the larger maize plant canopy providing larger photosynthetic area, attained when haricot bean interseeding was delayed, probably resulted in higher grain yield of maize. DOI: http://dx.doi.org/10.3126/ije.v3i3.11072 International Journal of Environment Vol.3(3) 2014: 126-138

Gestão de Striga asiatica em milho no Planalto Central de Angola - consociação com plantas-armadilha leguminosas e gramíneas

Maize intercropped field trials with the legumes Desmodium uncinatum cv. ‘D. Silver leaf’, Cajanus cajan, Mucuna pruriens, Tephrosia sp. and Crotalaria sp. and the trap grass Tripsacum laxum were conducted from 2008 until 2010, at Chianga, Huambo, Angola, to evaluate the effect of intercropping for the control of Striga asiatica and maize cv. ‘SAM3’ yield. Greenhouse trials with the trap grass T. laxum in clean and infested soils with the parasitic plant were also carried on. T. laxum grown in infested soils by S. asiatica both in greenhouse and field trials significantly duplicated weed seed emergence, comparatively with the sown of maize alone. By other side, in the maize-legumes trials, the results show that the intercropping of maize with legumes significantly reduced S. asiatica infestation and gave significantly higher grain yield of maize. These studies have confirmed the potentials of Tripsacum laxum as trap crop combined with maize x legume intercropping in the management of S. asiatica. Based on these results, this cultural strategy could reduce the parasitic plant seed bank and increase soil fertility and consequently maize yield.

English

An experiment was carried out in order to evaluate the productivity of soil amended with different animal wastes at the Teaching and Research Farm at the Faculty of Agriculture and Natural Resources Management, Ebonyi State University, Abakaliki. The field was laid out in randomized complete block design (RCBD) comprising of poultry droppings (PD), swine waste (SW), goat droppings (GD), cow dung (CD) and control (c) replicated four times. Maize variety (Oba Super II) was used as a test crop. The result indicated that bulk density, total porosity, aggregate stability, mean weight diameter and state of aggregation were significantly (P < 0.05) higher in poultry droppings amended plots compared to control. Soil pH, total N, Calcium, Potassium, Sodium, effective cation exchange capacity, percent base saturation and exchangeable acidity were significantly (P < 0.05) higher in plots amended with poultry droppings when compared to control. Plots amended with poultry droppings gave the highest grain yield of maize which was 64% higher than that of the control. Poultry droppings could be recommended for improved soil productivity in Abakaliki location. Key words: Animal wastes, amended, evaluation, productivity, soil.

Influence of Drip Fertigation and Intercropping on Yield, Agronomic Efficiency and Partial Factor Productivity of Maize

Field investigations were carried at Tamil Nadu Agricultural University during kharif 2008 and 2009 to study the effect of drip fertigation on nutrient use efficiency of maize (Zea mays) based intercropping systems. Results revealed that irrespective of different levels of fertilizer, fertigation significantly increased the partial factor productivity (PFP) and agronomic efficiency (AE) as compared to surface method of fertilizer application. Among the intercropping systems tested, higher nutrient use efficiency was realised under maize + vegetable coriander intercropping system. Partial Factor Productivity (PFP) decreased with increasing rates of fertigation. Drip fertigation with 50 per cent RDF in which 50 per cent of P and K as WSF resulted in higher PFP of 80.90 and 161.80 kg kg-1 N and P, respectively. The pooled data revealed that higher grain yield of maize (7309 kg ha-1) was observed under fertigation of 100 per cent RDF in which 50 per cent P and K as WSF. Drip fertigation of 100 per cent RDF (50 per cent P and K as WSF) increased the yield upto 55 per cent compared to surface irrigation and soil application of fertilizer. Fertigation with normal fertilizer increased the yield upto 18 kg per kg of nutrient applied, whereas water soluble fertilizer (50 per cent) increased the yield upto 25 kg per kg of nutrient applied.

Effect of cultural methods on Striga (Striga hermonthica (Del.)) Benth management and yield of cereals in the Savanna Zone of Nigeria: a review

Data were obtained from the research done in the Guinea Savanna (Zaria 11°11′N; 070 38′E) and Sudan Savanna (Maiduguri −11°51′N; 13°15′E) regions of Nigeria, respectively on different cultural methods of Striga control and management. In the Guinea Savanna, trials on the effects of nitrogen on the response of resistant and susceptible upland rice varieties to Striga hermonthica infestation and the effect of resistant and susceptible varieties of maize and crop rotation on Striga infestation was carried out, while the effect of inter-cropping trap crop (Bambaranut) with resistant sorghum varieties on S. hermonthica was studied in the Sudan Savanna Zone of Nigeria. In the Guinea Savanna, it was observed that a combination of upland rice variety, Faro 40 and an application of 90 kg N/ha in the wet season and WAB 56-50 upland rice variety and 120 kg N/ha in the dry season, respectively reduced Striga infestation and produced maximum grain yield. Also, the growing of resistant variety of maize (Across 97ITZ comp. I-W) after 1 or 2 years' rotation with cowpea or soybean was observed not only to be effective in Striga control, but resulted in higher grain yield of maize. In the Sudan Savanna, the use of resistant varieties of sorghum, 1CSV1002 and 1CSV1007 intercropped with bambaranut significantly reduced Striga infestation, but the grain yield of the resistant varieties was low. From these studies, Faro 40 with 90 kg N/ha application rate and WAB56–50 with 120 kg N/ha were suitable for the management of Striga and for higher grain yield of upland rice in both wet and dry seasons, respectively, while Across 97ITZ comp. I-W, resistant maize variety and 1 or 2 years rotation with cowpea or soybean were also the best for the management of S. hermonthica and for higher maize yield in the Guinea Savanna zone. Further research needs to be carried out in the Sudan Savanna to select a high yielding resistant variety of sorghum which when intercropped with bambaranut will not only control Striga infestation but will also give high grain yield.

Effect of Nitrogen Rates and Weed Control Treatments on Maize Yield and Associated Weeds in Sandy Soils

The effect of N levels, weed control treatments, and their interaction on maize yield and weed growth in sandy soils is not completely understood. Therefore, field experiments were conducted during 2005 and 2006 to determine if management can improve maize competitiveness with weeds, and thus achieve the yield potential of maize in sandy soils. The experiment included three N levels (300, 338, and 375 kg/ha) and five weed control treatments, e.g., hand hoeing twice, hand hoeing three times, fluroxypr + hoeing once, hoeing once + bispyribac-Na, and a nonweeded check. N rates affected dry weight of weeds growing with maize except with large crabgrass. Biomass of common purslane, considered a nitrophilous species, was increased by all N levels. Weeds were controlled by all treatments compared with the nontreated check; however, herbicide treatments were not superior to hand-hoeing treatments. Using more N favored growth and yield of maize more than weeds. Adding N fertilizer also improved most yield parameters. Highest grain yield of maize resulted at 375 kg/ha N. All weed control treatments improved grain yield two- to threefold compared with the nonweeded check. The interaction between N rates and weed control treatments had significant effects on dry biomass of common purslane and barnyardgrass, as well as grain index and biological yield parameters of maize. Grain yields were improved with fluroxypyr applied 2 wk after sowing (WAS) maize followed by one hand hoeing 6 WAS or hoeing at 3 WAS followed by bispyribac-Na applied 6 WAS. However, highest yields were obtained by hoeing early during the growing season.

Effect of residuce burning and fertilizer application on soil nutrient dynamics and dry grain yield of Maize ( Zea may s L.) in an Alfisol.

Field study was conducted for two cropping seasons to evaluate the effects of residue burning and fertilizer application on soil nutrient dynamics and maize yield in an alfisol. The treatments consisted of eight fertilizer treatments applied either as single element or in combinations of N,P and K (control, NPK,NP,NK,PK,N,P,K) as 60kg N ha as urea, 30 kg P ha-1 as single super phosphate and 30kg K ha-1 as muriate of potash, and two levels of residue management, namely; no ash addition (bare plot) and slash, burn and incorporated with hoe. The main fallow vegetation consisted of Chromolaena odorata, Tridax procumbens and some Imperata cylindrical. Burning of residue led to significant increase in soil nitrate-nitrogen, available phosphorus, sulphur, exchangeable calcium, and potassium and soil organic matter as early as 30 days after planting maize. The increment was more pronounced in soil available K while the application of fertilizer N,P,K, singly or in combinations also enhanced the accumulation on these nutrients in the soil. The increase in these nutrients was not sustained till harvest. Soil nutrient levels fall below pre-treatment level at plant harvest except soil available sulphur and potassium, which increase at harvest. Addition of N,P,and K or ash produced the highest maize grain yield. For a sustained increase in soil nutrient level plant ash incorporation should be complemented with inorganic fertilizers particularly with soils from short fallow period. Nigerian Journal of Soil Science Vol. 17 2007: pp. 71-80

Effect of double no-till and permanent raised beds on productivity, profitability and physical properties of soil in maize (Zea mays)wheat (Triticum aestivum) cropping system under Indo-Gangetic plains of India

A field experiment was conducted at Indian Agricultural Research Institute, New Delhi on sandy loam soil dur- ing 2010 to 2012 to study the effect of tillage and crop establishment techniques, and residue management on maize ( Zea mays L.)wheat [ Triticum aestivum (L.) emend. Fiori &amp; Paol] cropping system. Results indicated that permanent beds with residue retention (PB+R) and fresh beds with crop residue incorporation (FB+R) were found comparable with respect to yield and yield attributes both in maize and wheat. FB+R recorded 25.0 and 8.3 % higher grain yield of maize and wheat, respectively compared to conventional tillflat (CTF). Likewise, PB+R gave 25.0 and 28.6% higher grain yield of maize and wheat, respectively over CT F. Further, PB+R gave 3.5% higher system productivity compared to FB+R. PB+R gave the highest net returns of maize (39.2 103 /ha), wheat (50.5 103 /ha) and the cropping system (89.7 103 /ha) followed by FB+R and zero till flat with residue retention (ZTF+R). At upper soil surface (010 cm), lowest bulk density and soil penetration resistance was ob- served in FB+R followed by PB+R. Among all the tillage, crop establishment, and residue management tech- niques, ZTF+R gave lowest yield and yield attributes, and recorded highest bulk density in upper soil surface.

Tillage and legume mulching effects on moisture conservation and productivity of rainfed maize (Zea mays)wheat (Triticum aestivum) cropping system

A field experiment was conducted at Selakui, Dehradun from 2001 to 2004 to study the effect of tillage, viz. con- ventional tillage (CT) and minimum tillage (MT); and weed-control practices, viz. chemical and mechanical weed- ing along with legume mulching, viz. in situ grown sunnhemp (Crotalaria juncea L.) and subabul [Leucaena leucocephala (Lam.) de Wit] on soil moisture conservation, crop productivity and soil health in maize (Zea mays (Triticum aestivum L. emend Fiori &amp; Paol.) cropping system. CT gave higher grain yield of maize (+0.11 to O. 17 t/ha), but wheat performed equally well under CT (2.48 tiha) and MT conditions (2.36 t/ha). Chemical weeding with herbicides (alachlor in maize and isoproturon in wheat) resulted in 7.8 and 9.9% higher yield of maize and wheat, respectively over mechanical weeding. Beneficial effect of live mulching with sunnhemp or Leucaena was similar (12.314.7%), while their combined application increased the maize yield by 19.1% over no mulching. Further, enhanced soil moisture conservation due to mulching at maize harvest led to greater productiv- ity of wheat by 16.1% with sunnhemp or Leucaena, and 27.0% with sunnhemp + Leucaena. Nitrogen uptake of maize and wheat increased significantly with chemical weeding and legume mulching, but tillage practices made no effect on wheat while in maize it was lower under MT. Wheat gave 45 times more net retums than maize, and the net B : C ratio of the system was &gt; .O with chemical weeding and legume mulching. Tillage and weed-control practices made no effect on organic C and total N status of soil but legume mulching improved these parameters and reduced bulk density associated with increased infiltration rate. It was concluded that CT along with legume mulching in maize and MT in wheat, and chemical weeding of both the crops was beneficial for improving moisture and nutrient conservation, and achieving higher productivity and profitability of maizewheat cropping system un- der Doon valley conditions.

Optimization of nitrogenous fertilizers using leaf-colour chart for irrigated hybrid maize (Zea mays) grown in Vertisol of sub-tropical India

A field experiment was conducted at Raichur, Karnataka, India, during the rainy seasons of 2016 and 2017, to study the response of hybrid maize leaf-colour chart (LCC) to N and evaluate threshold to enhance crop yields, N- use efficiency (NUE) by altering splits as per crop need guided by LCC. Treatments included LCC thresholds of 1, 2, 3, 3.5, 4, 4.5, 5 and 6 compared with fixed splits at definite growth stages and absolute control. Application of 30 kg N/ha, whenever greenness of first fully opened leaf from the top was less than shade of the thresholds on the LCC. Hybrid maize showed significant response to application of N up to 120 kg N/ha in 3 equal split doses. Be- yond this level, fertilizer NUE was significantly reduced. The LCC &lt; 5 proved better than other LCC shades for guiding real-time N management and achieving higher NUE. Application of 80110 kg N/ha using threshold LCC &lt; 4.5 inclusive of 62.5 kg N/ha basal resulted in higher grain yield of maize which was at par with the application of 150 kg N/ha applied in 3 equal split doses.