Effects of Nitrogen Application and Plant Spacing on Photosynthesis

Taking the flue-cured tobacco variety K326 as material, the research conducted field experiment to study the effects of quantity of nitrogen fertilizer and plant spacing on tobacco photosynthesis, dry matter accumulation, yield and quality. The results showed that the CO2 concentration in the intercellular space was the highest in M2N2, and was the lowest M1N1, with extremely significant differences. The net photosynthetic rate was the highest in M2N2 and the lowest in M3N3. In resettling and squaring stages, with the same spacing, the weights of root dry matter were growing in different treatments upon nitrogen quantity; the weight of dry matter in stem showed irregularity; the dry matter of leaf accumulation kept slow in early and end stages, but fast in middle stage. In the same growth stage, dry matter accumulation of leaf was higher than those of stem and root, and the proportion of tobacco leaf to the whole plant was decreasing though always kept above 50%. In general, it can be concluded from yield, quality and output value that M2N2 performed the best.

Effects of Plant Spacing and Finger Sticking Area Settings for Machine Transplanting on Yield of Double-season Early Rice

The effects of rice transplanters＇ transplanting settings（plant spacing and finger sticking area） on rice yield were investigated in two early-season rice cultivars：hybrid rice cultivar（Zhuliangyou 819） and conventional rice cultivar（Zhongjiazao 17）.The results showed that,different transplanting settings resulted in different numbers of transplanted basic seedlings,and the rice yield was significantly correlated with the number of transplanted basic seedlings.The number of transplanted basic seedlings increased with the decrease of plant spacing and the increase of finger sticking area.The rate of lost hills of machine transplanting decreased with the increase of finger sticking area.The leaf area index and amount of dry matter accumulation were highly correlated with the number of transplanted basic seedlings.The average yield of the rice transplanted with a plant spacing of11.5 cm was higher than that with a plant spacing of 13.8 cm.In the field transplanted with the rice under the plant spacing of 13.8 cm,the rice yield increased with the increase of finger sticking area,and the finger sticking area of 2.23 cm2 showed the highest rice yield of 8 174.16 kg/hm2 of Zhuliangyou 819 and 7 925.54kg/hm2 of Zhongjiaozao17.In the field transplanted with the rice under the plant spacing of 11.5 cm,the rice yield was the highest with the finger sticking area of 1.83 cm2,and then decreased with the large finger sticking area.Under the plant spacing of 11.5 cm,the highest rice yields of Zhuliangyou 819 and Zhongjiaozao17 were 8 492.94 kg/hm2 and 8 000.23 kg/hm2,respectively.Therefore,the preferred machine transplanting settings for double-season early rice are a plant spacing of11.5 cm and a finger sticking area of 1.83 cm2,while the finger sticking area should be increased to 2.23 cm2 for conventional rice cultivars.

Response of French Bean Cultivars to Plant Spacing Under Agroclimatic Condition of Baffa

This experiment was carried out at Mansehra during cropping season of 2013. There were three French bean cultivars and four different plant spacings. The experiment was laid out on a Randomized Complete Block Design （RCBD） with three replications. Different cultivars, plant spacings and their interactions significantly influenced all the parameters studied. Maximum days to flowering （59.33） and seed maturity （97.66） were recorded in cultivar Komal Green grown at 15 cm spacing, while, maximum 100-grain weight （42.20 g） was noted in cultivar Peshawar Local grown at 60 cm spacing. However, maximum fresh pod yield·plant^-1 （109.67 g）, number of seed·pod^-1 （7.99） and seed yield.hm2 （1 4373 kg） were recorded in cultivar Paulista grown at spacing of 45 cm. Whereas, maximum plant height （40.50 cm） was noticed in cultivar Paulista grown at 15 era plant spacing. While, the least number of days to flowering （50.33） and to seed maturity （85.66） were taken by cultivar Paulista grown at 60 cm plant spacing. Likewise, minimum seed yield （311.9 kg·hm^2） was recorded in plants of cultivar Komal Green spaced at 60 cm plant spacing. While, minimum fresh pod weight, plantI （67.00 g） and number of seed·pod^-1 （4.66） were attained in cultivar Peshawar Local grown at 15 cm plant spacing, whereas, minimum plant height （27.59 cm） and 100-grain weight （15.60 g） were recorded for cultivar Komal Green grown at 45 and 15 cm, respectively.

Effect of Plant Spacing on Growth and Grain Yield of Soybean

In the Philippines, rice monoculture systems are common. Compared to these systems, the rice-soybean cropping system may prove more water-efficient and there is a trend of increasing soybean area in the response to water scarcity and need for crop diversification in the Philippines. A field study was conducted to evaluate the effect of row and plant to plant spacing (20 × 10, 20 × 5, 40 × 10, and 40 × 5 cm) on growth and yield of soybean. Plant height was not influenced by the plant geometry. Spacing, however, influenced leaf area and shoot biomass of soybean. Plants grown at the widest spacing (i.e., 40 × 10 cm) produced lowest leaf area and shoot biomass at 6 and 12 weeks after planting. Leaf area and shoot biomass at other three spacing were similar. There was a negative and linear relationship between weed biomass and crop shoot biomass at 6 and 12 weeks after planting. Grain yield of soybean was not affected by plant geometry and it ranged from 1.3 to 1.9 t·ha-1 at different spacing.

Estimation of morphological traits of foliage and effective plant spacing in NFT-based aquaponics system

Deep learning and computer vision techniques have gained significant attention in the agriculture sector due to their non-destructive and contactless features.These techniques are also being integrated into modern farming systems,such as aquaponics,to address the challenges hindering its commercialization and large-scale implementation.Aquaponics is a farming technology that combines a recirculating aquaculture system and soilless hydroponics agriculture,that promises to address food security issues.To complement the current research efforts,a methodology is proposed to automatically measure the morphological traits of crops such as width,length and area and estimate the effective plant spacing between grow channels.Plant spacing is one of the key design parameters that are dependent on crop type and its morphological traits and hence needs to be monitored to ensure high crop yield and quality which can be impacted due to foliage occlusion or overlapping as the crop grows.The proposed approach uses Mask-RCNN to estimate the size of the crops and a mathematical model to determine plant spacing for a self-adaptive aquaponics farm.For common little gem romaine lettuce,the growth is estimated within 2 cm of error for both length and width.The final model is deployed on a cloud-based application and integrated with an ontology model containing domain knowledge of the aquaponics system.The relevant knowledge about crop characteristics and optimal plant spacing is extracted from ontology and compared with results obtained from the final model to suggest further actions.The proposed application finds its signifi-cance as a decision support system that can pave the way for intelligent system monitoring and control.

Sorghum Productivity and Its Farming Feasibility in Dryland Agriculture:Genotypic and Planting Distance Insights

Sorghum(Sorghum bicolor L.Moench)is an essential food crop for more than 750 million people in tropical and sub-tropical dry climates of Africa,India,and Latin America.The domestic sorghum market in Indonesia is still limited to the eastern region(East Nusa Tenggara,West Nusa Tenggara,Java,and South Sulawesi).Therefore,it is crucial to carry out sorghum research on drylands.This research aimed to investigate the effect of sorghum genotype and planting distance and their interaction toward growth and sorghum’s productivity in the Gunungkidul dryland,Yogyakarta,Indonesia.In addition,the farm business analysis,including the feasibility of sorghum farming,was also examined.The research used a randomized complete block design(RCBD),arranged in a 5×4 factorial with 3 replicates.The first treatment consisted of 5 varieties(2 high-yielding varieties(Bioguma 1 and Kawali)and 3 local sorghum varieties(Plonco,Ketan Merah,and Hitam Wareng)).The second treatment consisted of 4 levels of planting distance,namely 50×20 cm,60×20 cm,70×15 cm,and 70×20×20 cm.Analysis of variance was used to analyze the data,where Duncan’s multiple range test(DMRT)was used post hoc.Plant height,panicle height,panicle width,panicle weight,stover weight,grains weight/plot,and productivity were significantly affected by sorghum varieties(p<0.05).However,there was no significant effect from the planting distance treatment and no interaction between planting distance and varietal treatments.Ketan Merah had the highest height,panicle length,and panicle width,while Bioguma 1 had the highest stover weight,panicle weight,grain weight/plot,and productivity.There was a significant linear regression equation,i.e.,productivity=0.0054–0.0003 panicle height+0.4163 grains weight/plot.Our findings on farm business analysis suggested that four out of five tested sorghum varieties were feasible to grow,except for the Ketan Merah variety.The most economically profitable sorghum variety to grow in Gunungkidul dryland was Bioguma 1.

Response of seed yield and fatty acid compositions for some sunflower genotypes to plant spacing and nitrogen fertilization

A field experiment was conducted at the experiment Farm of Kafr-El-Hamam Research Station,Zagazig,Sharkia Governorate,Agricultural Research Center,Egypt during the two successive summer seasons of 2015 and 2016 to achieve the highest yield and good oil quality of three tested sunflower genotypes.In both seasons,the experiment was conducted using the split split plot design in randomized complete block design with three replicates arrangement keeping plant spaces(15,20 and 25 cm apart between hills)in main plots,nitrogen fertilization levels(15,30 and 45 N fad.^-1)in sub plots and sunflower genotypes(Giza 102,Sakha 53 and promising line of L120)in sub sub plots.Yield and quality traits were significantly influenced by plant spaces,nitrogen fertilization levels and genotypes as well as interactions in both seasons and their combined analysis.The wider plant spacing of 25 cm seems to be a good compromise between the highest seed yield fad.^-1 and good acid composition of oil.Gradually increasing of nitrogen fertilization level had a positive reflected on yield and desirable acid composition of oil.Sakha 53 was ranked in the first order in stem diameter,head diameter,100-seed weight,seed weight plant^-1,flowered late and hence seed yield fad.^-1 as well as seed oil content whereas,Giza 102 characterized with its contained the highest proportion of oleic and linoleic unsaturated fatty acids.The highest values of head diameter,100-seed weight,seed weight plant^-1 and hence seed yield fad.^-1 as well as the highest proportion of oleic and linoleic unsaturated fatty acids composition were obtained by grown sunflower cv.Sakha 53 at wider spacing of 25 cm with application of nitrogen fertilization levels of 45 N fad.^-1.Correlation and path analyses revealed that 100-seed weight and head diameter had the highest direct and indirect influence on seed weight plant
1,at the same time also,oleic acid content and linoleic acid content had the highest direct and indirect effect influence on seed oil content indicating their importance as selection criteria to improve yield and oil quality of sunflower.

Effect of Plant Geometry on Growth and Yield of Corn in the Rice-Corn Cropping System

The rice-corn cropping system is increasing in Asia in response to increased demand of corn for feed. A field study was conducted to evaluate the effect of plant geometry (row and plant to plant spacing: 50 × 20, 50 × 30, 75 × 20, and 75 × 30 cm) on growth and yield of corn. Plant height and leaf production per plant were not influenced by the plant geometry. Spacing, however, influenced leaf area, aboveground shoot biomass, and yield of corn per unit area. Highest leaf area, shoot biomass, and yield (8.2 t·ha-1) were produced by plants grown at 50 × 20 cm spacing. The results of this study suggest that narrow rows and plant to plant spacing may increase grain yield by increasing crop growth rates. Plant geometry could be modified to improve yield of corn in the rice-corn cropping system, and thereby increase productivity of the system.

Growth and wood properties of a 38-year-old Populus simonii 3 P.nigra plantation established with different densities in semi-arid areas of northeastern China

To characterize the effects of plantation densities on the growth characteristics(diameter at breast level,tree height and volume)and the common wood properties,38-year-old Populus simonii 9 P.nigra clones planted with four levels of spacing(2 m 92 m,3 m 93 m,4 m 94 m,and 5 m 95 m)in a semi-arid area in northeastern China were examined.The results of ANOVA showed significant differences(P\0.01)for all the investigated growth traits and wood properties under different plantation densities,except for the chemical composition of wood.The repeatability and phenotypic variations of all the traits varied from 0.34 to 0.99 and from 13.45 to 59.65%,respectively.Except for wood density,which was significantly negatively correlated with the growth traits,a positive correlation was observed between the growth traits and all the other wood mechanical properties.However,most of the correlations between the growth traits and the chemical composition of the wood were not significant.The path analysis for the wood mechanical characteristics and the growth in the prediction of volume were significant and ranged from 0.18 to 0.72 for wood density and diameter at breast height,respectively,while those for the chemical composition of wood ranged from 0.001 to 0.336,which showed a low impact on the volume.The highest stand volume(610 m3)per hectare was observed with the 2 m 92 m spacing,which consequently provided a high total price and income,while a high individual volume growth per tree was observed with the 5 m 95 m spacing.The results suggested that for the poplar trees younger than 40 years in a semi-arid area in China,2 m 92 m spacing is suitable for obtaining a high volume per hectare,while 5 m 95 m spacing is best for obtaining a high individual volume per tree.

Liquid Organic Fertilizer and Planting Space Influencing the Growth and Yield of Rice （Oryza sativa L.） in System of Rice Intensification （SRI） Methods

This research aimed to know the influence of liquid organic fertilizer and planting space to the growth and yield of rice in System of Rice Intensification （SRI） methods. The research was conducted in Palur, Sukoharjo, laid on 98 m above sea level from December 2008 to April 2009. Experimental design used was Randomized Completely Block Design with two factors of treatment. The first factor was liquid organic fertilizer; consist of control, cebreng leaf, rumen of goat, banana tree hump, and maja fruit. The second factor was planting space; consisting of 25 cm × 25 cm, 30 cm ×30 cm and 35 cm× 35 cm. There were 15 combinations of treatment and each repeated three times. Data analyzed with F test at 5% and DMRT at 5%. Research result showed that liquid organic fertilizer of maja fruit serves the best on variable of stalk length. Planting space of 35 cm × 35 cm serves the best on variable of plant height, number of total sapling, number of productive sapling, weight of dry plant, weight of rice per clump, and weight of 1,000 rice grains. There is no interaction between liquid organic fertilizer and planting space on all variables.

Optimization design and experiment of the variable differential gear train planting mechanism

In order to improve the adaptability of the planting mechanism for different plant spacings,a variable differential gear train planting mechanism based on precise pose and trajectory control was proposed by combining the open chain 2R rod group and the variable differential gear train.According to the pose requirements of receiving seedling point,transporting seedling point and planting point,three precise pose points of constrained planting trajectory were determined.Through the three-position motion generation structural synthesis method,combined with computer-aided optimization design software,a set of mechanism parameters that meet the planting requirements were optimized.Based on the optimized mechanism parameters,by only changing the coordinates of two trajectory shape control points,three planting trajectories with key point position information adapted to 300 mm,400 mm and 500 mm plant spacing were obtained by interpolation,and three pairs of total transmission ratio of three groups of variable differential gear trains were calculated.When distributing the total transmission ratio of the mechanism,the fixed axis gear train and the differential gear train are combined.The fixed axis gear train included a pair of non-circular gear pairs and a pair of positive gear pairs,which were convenient for disassembly and assembly.The former drives the sun gear at variable speed,and the latter drives the planet carrier at uniform speed.Based on this structure,the transmission ratio of the positive gear pair is-1,and the transmission ratio of the differential gear train is 0.5.The sub-transmission ratio of the single-stage non-circular gear pair was calculated and the pitch curves of three pairs of noncircular gears were solved.Three pairs of non-circular gear pairs with different transmission ratios were replaced in turn and three sets of planting mechanisms were modeled in three dimensions.The virtual prototype motion simulation was completed by ADAMS software,and the physical prototype was built for vegetable pot seedling planting test.The theoretical solution was consistent with the attitude and trajectory of the actual test.When the test sample size was 100 plants,the actual average plant spacing was measured to be 303 mm,402 mm,and 503 mm,with errors of 1.3%,1.25%,and 1.88%.The width of the moving hole was 72 mm,70 mm,and 71 mm,and the planting success rate were 94%,96%,and 95%.The test results verified the correctness of the optimization design results of the mechanism,indicating that the variable differential gear train planting mechanism can adapt to a variety of plant spacing and has good planting effect.

Influence of Planting Spacing on Mechanical Properties of Eucalyptus grandis × E. urophylla Planted in China

The objective of this study was to understand influence of planting spacing on mechanical properties of Eucalyptus grandis × E. urophylla planted as a potential species for solid wood products in China. Four trees at age of 13 were selected from each of 6 groups of planting spacing and a total of 24 sampling trees were selected from the Dongmen Forestry Center of Guangxi Province in China. Furthermore, a one-meter-long log from each tree was cut into small blocks for wood properties testing. MOE, MOR and compression strength parallel to wood grain were determined in accordance with Chinese standards. In addition, wood density and shrinkage properties were measured. Statistical analysis by SAS software indicated significant differences among the 6 groups of planting spacings on the air-dried density, radial shrinkage and bending MOR properties at the 0.05 level, and also on the compression strength at the 0.10 level. However, it was observed that there is no significant differences among shrinkages in tangential and volume, and MOE.

Design and experiment on intelligent fuzzy monitoring system for corn planters

When sowing summer corn without tillage,it is necessary to ensure that the furrow opener is free from straw congestion and that the spacing of the sowing can be adjusted according to the breeds of corn and the preset seeding rate per acre.On the basis of the structural features of newly developed no-tillage corn fertilizers,an intelligent fuzzy monitoring system for corn planters was developed in this study.The system facilitates automatic control of the spacing adjustment and the status monitor for the fertilizer tank,seed tank,and seeding orifice.According to the preset number of rows,line spacing,number of plants per acre,and seed germination rate,the control rate can be calculated through designing in surveillance software.The control rate is output to the fuzzy controller through the digital output module of the CAN bus.Fuzzy control is applied to the DC motor for stepless adjustment of the spacing.A system for video surveillance of the working status of a planter is developed for displaying a real-time video image of the planter operation and achieving an anti-congestion status monitoring of a no-tillage planting operation in a dusty environment.Through field trials,the detection accuracy was 91.4%.The seed-clogging fault-alarm accuracy was 96.0%.The entire system remained stable and reliable.