Relative effects of Azolla pinnata and its combination with chemical nitrogen fertilizer on growth, yield and N uptake of rice

1986 ◽  
Vol 106 (1) ◽  
pp. 107-112 ◽  
Author(s):  
D. P. Singh ◽  
P. K. Singh

SUMMARYField experiments conducted during wet and dry seasons with Ratna and Jaya varieties of rice (Oryza sativa Linn.) indicated that the use of Azolla pinnata as fertilizer increased growth in terms of number of tillers, leaf area index, dry-matter production, grain yield, N uptake and its accumulation in different plant parts. Azolla incorporation before planting in addition to 30 kg N/ha produced higher grain yields of both the rice varieties than 60 kg N / h a during the two seasons, while Azolla grown as an intercrop with rice plus 30 kg N/ha was superior to the 60 kg N treatment in grain production of Jaya during the wet season. Azolla incorporation before planting and also once intercropped with rice produced more grain yield than 60 kg N during the wet season. Among Azolla treatments, Azolla twice intercropped with rice produced comparatively lower grain yield. Azolla application increased the number of panicles/m2, number of grains/panicle and reduced sterility during both seasons. The N uptake of the rice crop in the treatments of Azolla incorporation before planting or intercropped once with rice in combination with 30 kg N/ha was similar to that of the 60 kg N/ha whereas the treatment of Azolla incorporation before planting plus once intercropped was similar during the wet season only.

1988 ◽  
Vol 24 (2) ◽  
pp. 183-189 ◽  
Author(s):  
D. P. Singh ◽  
P. K. Singh

SUMMARYThe effects of phosphorus fertilizer and the insecticide carbofuran on the growth and N2-fixation of Azolla pinnata and on the growth, grain yield and nitrogen uptake of intercropped rice were examined in a wet and a dry season. Treatment with phosphorus or carbofuran increased the biomass of Azolla and the amount of nitrogen fixed (nitrogen yield) in both seasons, but the response was much better in the dry season. Azolla inoculation at 1.0 t ha−1 resulted in a greater bio mass and nitrogen yield than inoculation at 0.5 t ha−1. In the dry season, a combination of phosphorus and carbofuran enhanced the growth and N2-fixation of Azolla more than either treatment alone. Carbofuran treatment slowed the rate of decomposition of Azolla, particularly in the dry season. The plant height, leaf area index and dry matter production of rice at flowering time were increased in the plots treated with phosphorus or carbofuran in the wet season and these treatments increased rice grain yield and nitrogen uptake in both the wet and dry seasons.


Agronomy ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1831
Author(s):  
Sachesh Silwal ◽  
Surya P. Bhattarai ◽  
David J. Midmore

Modern rice varieties adapted to aerobic (dryland) conditions have expanded to new rice growing systems thanks to their plasticity in adapting to rainfed and irrigated conditions. This is important because, as water becomes scarce in paddy rice regions (as it is already in Australia), there will be a move towards tropical to subtropical dryland rainfed rice with attendant problems of drought and low temperature. To assess rice adaptability in the wet season of the semi-arid subtropical conditions of coastal central Queensland, field experiments were established for a late season (in January) planting in 2014 and early season planting in November 2015 with 13 varieties developed by Australian Agriculture Technologies (AAT) Ltd were seeded in a vertisol soil. This was to assess their adaptation to rainfed conditions and their response to strategic irrigation. Water scarcity and low temperature prior to and at flowering were important factors constraining yield. Early flowering varieties in the late season planting escaped the otherwise cold and drought stress during the reproductive stage and had higher yields. In the second year, earlier planting made possible with strategic irrigation avoided the low temperature constraint on yield, but without follow-up strategic irrigation, yields were still low. The average yield of varieties increased from 1.5 times (AAT 4) to 16.3 times (AAT 15) with strategic irrigation compared with rainfed yields averaged across years. The increase in yield with strategic irrigation was associated with a greater leaf area index, spikelet fertility, and instantaneous water use efficiency during flowering. Strategic irrigation concentrated roots in the top 15 cm, but differences in yield between varieties under rainfed conditions were not related to root properties. It is important to consider variations in flowering time, yield potential, and drought patterns when developing rice varieties for rainfed semi-arid tropical conditions, as well as when quantifying the benefits of strategic irrigation.


2021 ◽  
Vol 64 (2) ◽  
pp. 142-159
Author(s):  
Asad Ali Khan ◽  
Inamullah Khan ◽  
Muhammad Faheem Jan ◽  
Waqas Liaqat ◽  
Asim Muhammad ◽  
...  

Application of macronutrients in less amount along with improper application method(s) are the major factors for low yield. Experiments were designed with the objectives to determine the optimum rate of nitrogen (N) and potassium (K) along with suitable application method to minimize nutrients losses. The experimental site was New Developmental Farm of the University of Agriculture Peshawar and  experiments were conducted for two consecutive years i.e. 2010-11 and 2011-12. After analysis, the results indicated that both N and K significantly affected days to phenology (anthesis and maturity). Days to phenology increased linearly with increase in rate of N and K and more days to phenology were recorded when both were at their highest rates. Similarly plant height, leaf area/tiller, flag leaf area, leaf area index, leaf area duration, grain yield, N uptake by grains and straw were increased with increasing level of N and K and attained maximum value when N and K was applied at the rate of 180 and 90 Kg/ha, respectively. Nutrients application method significantly affected plant height, leaf area/tiller, flag leaf area, grain yield and N uptake by straw and grains with maximum values for these traits were recorded when nutrients  (N and K) were applied in such a combination that 15% nutrients were supplied through foliar and 85% through soil application. Application methods had a non-significant effect on days to phenology, leaf area index and leaf area duration. It is concluded from the results that application of N and K at the rate of 180 and 90 Kg/ha respectively in such a way that 15% is applied through foliar spray and 85% through soil application improved growth, yield and N uptake of wheat crop under the semi-arid climate.    


Agronomy ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 76
Author(s):  
Aloysius Beah ◽  
Alpha Y. Kamara ◽  
Jibrin M. Jibrin ◽  
Folorunso M. Akinseye ◽  
Abdullahi I. Tofa ◽  
...  

This paper assessed the application of the Agricultural Production Systems sIMulator (APSIM)–maize module as a decision support tool for optimizing nitrogen application to determine yield and net return of maize production under current agricultural practices in the Nigeria savannas. The model was calibrated for two maize varieties using data from field experiments conducted under optimum conditions in three locations during the 2017 and 2018 cropping seasons. The model was evaluated using an independent dataset from an experiment conducted under different nitrogen (N) levels in two locations within Southern and Northern Guinea savannas. The results show that model accurately predicted days to 50% anthesis and physiological maturity, leaf area index (LAI), grain yield and total dry matter (TDM) of both varieties with low RMSE and RMSEn (%) values within the range of acceptable statistics indices. Based on 31-year seasonal simulation, optimum mean grain yield of 3941 kg ha−1 for Abuja, and 4549 for Kano was simulated at N rate of 120 kg ha–1 for the early maturing variety 2009EVDT. Meanwhile in Zaria, optimum mean yield of 4173 kg ha–1 was simulated at N rate of 90 kg ha−1. For the intermediate maturing variety, IWDC2SYNF2 mean optimum yields of 5152, 5462, and 4849 kg ha−1, were simulated at N application of 120 kg ha−1 for all the locations. The probability of exceeding attainable mean grain yield of 3000 and 4000 kg ha−1 for 2009EVDT and IWDC2SYNF2, respectively would be expected in 95% of the years with application of 90 kg N ha−1 across the three sites. Following the profitability scenarios analysis, the realistic net incomes of US$ 536 ha–1 for Abuja, and US$ 657 ha−1 for Zaria were estimated at N rate of 90 kg ha−1 and at Kano site, realistic net income of US$ 720 ha–1was estimated at N rate of 120 kg ha−1 for 2009EVDT.For IWDC2SYNF2, realistic net incomes of US$ 870, 974, and 818 ha−1 were estimated at N application of 120 kg ha−1 for Abuja, Zaria, and Kano respectively. The result of this study suggests that 90 kg N ha−1 can be recommended for 2009EVDT and 120 kg N ha–1 for IWDC2SYNF2 in Abuja and Zaria while in Kano, 120 kg N ha−1 should be applied to both varieties to attain optimum yield and profit.


1975 ◽  
Vol 26 (3) ◽  
pp. 497 ◽  
Author(s):  
EAN Greenwood ◽  
P Farrington ◽  
JD Beresford

The time course of development of a lupin crop was studied at Bakers Hill, Western Australia. The aim was to gain insight into the crop factors influencing yield. Weekly measurements were made of numbers and weights of plant parts, and profiles of roots, leaf area and light interception. A profile of carbon dioxide in the crop atmosphere was taken at the time of maximum leaf area, and the net carbon dioxide exchange (NCE) of pods was estimated for three successive weeks. The crop took 10 weeks to attain a leaf area index (LAI) of 1 and a further 9 weeks to reach a maximum LAI of 3.75, at which time only 33% of daylight reached the pods on the main axis. Once the maximum LAI was attained at week 19, leaf fall accelerated and rapid grain filling commenced almost simultaneously on all of the three orders of axes which had formed pods. Measurements of NCE between pods on the main axis and the air suggest that the assimilation of external carbon dioxide by the pods contributed little to grain filling. Grain dry weight was 2100 kg ha-1 of which 30%, 60% and 10% came from the main axis, first and second order apical axes respectively. Only 23% of the flowers set pods and this constitutes an important physiological limitation to grain yield.


2011 ◽  
Vol 150 (5) ◽  
pp. 584-594 ◽  
Author(s):  
V. A. PAPPA ◽  
R. M. REES ◽  
R. L. WALKER ◽  
J. A. BADDELEY ◽  
C. A. WATSON

SUMMARYIntercropping systems that include legumes can provide symbiotically fixed nitrogen (N) and potentially increase yield through improved resource use efficiency. The aims of the present study were: (a) to evaluate the effects of different legumes (species and varieties) and barley on grain yield, dry matter production and N uptake of the intercrop treatments compared with the associated cereal sole crop; (b) to assess the effects on the yields of the next grain crop and (c) to determine the accumulation of N in shoots of the crops in a low-input rotation. An experiment was established near Edinburgh, UK, consisting of 12 hydrologically isolated plots. Treatments were a spring barley (Hordeum vulgare cvar Westminster) sole crop and intercrops of barley/white clover (Trifolium repens cvar Alice) and barley/pea (Pisum sativum cvar Zero4 or cvar Nitouche) in 2006. All the plots were sown with spring oats (Avena sativa cvar Firth) in 2007 and perennial ryegrass in 2008. No fertilizers, herbicides or pesticides were used at any stage of the experiment. Above-ground biomass (barley, clover, pea, oat and ryegrass) and grain yields (barley, pea and oat) were measured at key stages during the growing seasons of 2006, 2007 and 2008; land equivalent ratio (LER) was measured only in 2006. At harvest, the total above-ground biomass of barley intercropped with clover (4·56 t biomass/ha) and barley intercropped with pea cvar Zero4 (4·49 t biomass/ha) were significantly different from the barley sole crop (3·05 t biomass/ha; P<0·05). The grain yield of the barley (2006) intercropped with clover (3·36 t grain/ha) was significantly greater than that in the other treatments (P<0·01). The accumulation of N in barley was low in 2006, but significantly higher (P<0·05) in the oat grown the following year on the same plots. The present study demonstrates for the first time that intercrops can affect the grain yield and N uptake of the following crop (spring oats) in a rotation. Differences were also linked to the contrasting legume species and cultivars present in the previous year's intercrop. Legume choice is essential to optimize the plant productivity in intercropping designs. Cultivars chosen for intercropping purposes must take into account the effects upon the growth of the partner crop/s as well as to the following crop, including environmental factors.


1970 ◽  
Vol 8 (2) ◽  
pp. 207-212
Author(s):  
MA Haque

Two pot and two field experiments were conducted at Patuakhali Science and Technology University research farm to investigate the contribution of tidal submergence to phosphorus nutrition and yield of rice. Pot and field experiments were conducted in the Aus and Aman seasons of 2009, respectively. The factorial experiments include two levels of water source- i) tidal water and ii) ground water, and three levels of fertilizers- i) absolute control (no fertilizer), ii) NK (P omission) and iii) NPK (P addition). The rice varieties used were BRRI dhan27 (HYV) and Local Mala (Traditional variety) in Aus season and BR23 (HYV) and Lalmota (Traditional variety) in Aman season. A general increase in growth, yield and yield contributing parameters were found due to irrigation with tidal water. Tidal water contributed about 21 (BR23) and 7 (Lalmota) % higher grain yield in Aman season 2009 and about 2 g biomass yield per pot (both BRRI dhan27 and Local Mala) in Aus season of 2009 compared to ground water. Phosphorus content of rice grain and straw was always higher when plants are irrigated with tidal water. In general tidal submergence increases P uptake of rice. Phosphorus uptake from tidal water treatments increased when plants were supplied with N and K fertilizer. Tidal submergence contributed about 5-6 kg P/ha in P omission plot, and about 12-14 kg P/ha in plots with added P.  Keywords: Phosphorus; Rice; Tidal submergence DOI: 10.3329/jbau.v8i2.7927 J. Bangladesh Agril. Univ. 8(2): 207-212 2010


2020 ◽  
Author(s):  
Aditi Bhandari ◽  
Nitika Sandhu ◽  
Jérôme Bartholome ◽  
Tuong-Vi Cao-Hamadoun ◽  
Nourollah Ahmadi ◽  
...  

Abstract Background Reproductive-stage drought stress is a major impediment to rice production globally. Conventional and marker-assisted breeding strategies for developing drought tolerant rice varieties are being optimized by mining and exploiting adaptive traits, genetic diversity; identifying the alleles and understanding their interactions with genetic backgrounds for contributing to drought tolerance. Field experiments were conducted in this study to identify marker-trait associations (MTAs) involved in response to yield under reproductive-stage drought. A diverse set of 280 indica-aus accessions was phenotyped for grain yield and nine yield-related traits under normal condition and under two managed drought environments. The accessions were genotyped with 215,250 single nucleotide polymorphism markers. Results The study identified a total of 220 significant MTAs and candidate gene analysis within 200kb window centred from GWAS identified SNP peaks detected these MTAs within/ in close proximity to 47 genes, 4 earlier reported major grain yield QTLs and 8 novel QTLs for 10 traits. The significant MTAs were majorly located on chromosomes 1, 2, 5, 6, 11 and 12 and the percent phenotypic variance captured for these traits ranged from 5 to 88%. The significant positive correlation of grain yield with yield-related traits, except flowering time, observed under different environments point towards their contribution in improving rice yield under drought. Seven promising accessions were identified for use in future genomics-assisted breeding program targeting grain yield improvement under drought. Conclusion These results provide a promising insight into the complex-genetic architecture of grain yield under reproductive-stage drought under different environments. Validation of major genomic regions reported in the study can be effectively used to develop drought tolerant varieties following marker-assisted selection as well as to identify genes and understanding the associated physiological mechanisms.


Author(s):  
Bidisha Borah ◽  
Kalyan Pathak

An investigation was carried out to determine an optimum micro-climate regimes for different promising varieties of rice for realizing higher yields under aerobic conditions. A field experiment was conducted in the Instructional Cum Research (ICR) Farm of Assam Agricultural University, Jorhat, Assam during autumn season of 2017. The experiment was laid out in a split-plot design with three replications. The treatments consisted of four micro-climatic regimes (M) in main plot viz., sowing of seed on 15th February (M1), 1st March (M2), 16th March (M3) and 1st April (M4) along with four different rice varieties (V) viz., CR-Dhan 205 (V1), CR-Dhan 203 (V2), CR-Dhan 204 (V3) and Inglongkiri (V4) in sub plot. The results of the experiment revealed that among the different micro-climatic regimes, the micro-climate associated with 1st April recorded positive effect on micro-climate related and yield parameters in terms of canopy temperature, light intensity, soil moister content, soil temperature, dry matter accumulation, leaf area index, number of effective tillers and grain yield (3004 kg/ha), followed by the micro-climate associated with 16th March sown crop. Among the varieties evaluated, CR-Dhan 203 recorded the highest value in terms of number of effective tillers (187/m2) followed by Inglongkiri, CR-Dhan 204 and CR-Dhan 205. The highest grain yield of 2860 kg/ha recorded in rice variety CR-Dhan 203 was significantly superior to that of other varieties except Inglongkiri. In terms of economics, the crop sown on 1st April recorded the highest net return (INR 51755 /ha) and B:C ratio (2.30) which was found to be the greatest.


2020 ◽  
pp. 1-7
Author(s):  
Teame Shimgabr ◽  
Negasi Gebereslasie ◽  
Haile Alene ◽  
Welesenbet Haftu ◽  
Nebyu Tsegay

Field experiments were conducted in three sites of Western Tigray, Ethiopia. The experiments aimed at identifying optimum the rate of the newly introduced NPS fertilizer impact with different levels on growth, yield attributes, yield and economics of sesame in vertisols of Western Tigray at the Humera station, Banat and Kebabo Kafta Humera and Tsegede Wereda’s. The treatments consisted of six levels of NPS 0, 50, 100, 150, 200 and 250 kg ha-1 and one blanket recommendation N and P was applied. The experiment was laid out in an RCBD with three replications. Yield of Sesame and yield related components showed significant difference (p < 0.001) compared to control. Results showed that number of branches plant-1, length of pod bearing zone (cm), plant height (cm), number of capsules plant-1, seeds capsule-1 and seed yield was significant differences at (P< 0.001) Grain yield increases from 444.8 kg ha-1 to 671.9 kg ha-1 as NPS and 444.8 kg ha-1 to 628 kg ha-1 as NP increases from 0 (control) to 100 kg ha-1 NPS and 41 kg N and 46 kg P205 ha-1 respectively. But NPS was not significant with blanket recommendation of N and P (41 kg N and 46 kg P205 ha-1), therefore no need to replace the NP by NPS fertilizer in the study area.


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