Effects of Planting Density on Yield and Mechanical Harvesting Loss Rate of Brassica napus L.

[Objective] This study aimed to explore agronomical measures to reduce the mechanical harvesting loss of rapeseed. [Method] Two rapeseed cultivars, Ningza 19 and Ningza 21, with certain pod-cracking resistance, were employed in field experiments. The two-factor split plot design and randomized complete block design were adopted. The rapeseed seeds were directly sowed with four different seeding rates （1.50, 2.25, 3.00 and 3.75 kg/hm2）. A total of four treatments were designed （112 500, 225 000, 337 500 and 450 000 plants/hm2）. After ripe, the rapeseed was harvested with harvester. Then the yield and harvesting loss rate were determined. [Result] When the planting density ranged from 112 500 to 450 000 plants/hm2, the mechanical harvesting loss rate was decreased with the increase of planting density （Ningza 19, 7.54%-4.01%; Ningza 21, 7.19%-3.81%）. The total loss rates were all below 5% for the high plant densities, 337 500 and 450 000 plants/hm2. High planting density had certain regulating effects on plant type of rapeseed, including reducing plant height, reducing biomass per plant, reducing branch pod numbers per plant, weakening crossing and tangling among stems and improving ripening uniformity of pods. All the changes above were all conducive to reducing mechanical harvesting loss. In addition, the test results showed after the pods grew to maturity, especially when pods were yellow and the moisture content in grains was reduced to 11%, the mechanical harvesting loss only accounted for about 1% of the total field loss. In addition, the shattering loss, caused by mild col- lision, represented more than 90%, and the cleaning loss, occurred during the threshing and cleaning process, represented 4%-8% of the total field loss. The un- harvesting loss accounted for approximately 1% of the total loss. The shattering loss is closely related to cultivar characteristics, planting density, production level and other agronomic factors. The cleaning loss is determined by properties of harvesting machines. The unharvesting loss depends on mechanical properties ad skills of workers or farmers who drive harvesting machines. [Conclusion] In order to reduce mechanical harvesting loss, the rapeseed production should be improved from the perspectives of agricultural machinery and agronomic measures.

Effects of Planting Density on Yield and Sourcesink Characteristics of Sweet Potato[Ipomoea batatas(L.) Lam]

[Objective] The aim was to resolve the issue of sparsely planting （37 500-40 500 plants/hm2） of sweet potato in hilly areas. [Method] The starch-oriented Jishu No.21 and raw-eating oriented Jishu No.22 were studied to explore effects of planting density on yield and sink and source characteristics of sweet potato. [IRe- suit] Leaf area index of Jishu No.21 and Jishu No.22 were increasing upon planting density. Leaf area index of the same planting density showed a single-peak curve. Specifically, leaf area index grew fast during the 40th-80th d after planting, and reached the peak on the 80th d after planting, followed by decreasing. What＇s more, ventilation and sunshine transmission both declined upon planting density, as well as the number of leaf, the number of branch, the length of vine, dry and fresh weights of stem and leaf. When planting density exceeded 75 000 plants/hm2, the yield of sweet potato dropped dramatically. Besides, the optimal planting density tended to be volatile upon cultivars. For example, the range of 45 000-60 000 plants/hm2 is the optimal planting density of Jishu No.21 and the range of 60 000-75 000 plants/hm2 is the optimal planting density of Jishu No.22. [Conclusion] It can be concluded that rational planting densities would well coordinate sweet potato growth of ground parts and underground parts to get a high yield by providing a rational group structure. Considering the optimal planting density differs upon cultivars, it is necessary to take genotype, environment, soil fertility and planting density into consideration in determining planting density.

Effects of Variety and Planting Density on Mung Bean Eco-Physiology and Yield in the Southeastern US

Mung bean (Vigna radiata L. Wilczek.) is a warm-season, C3 pulse crop of the legume family that has been widely cultivated in Asian countries. As the demand for mung bean continues to increase in the United States, the ecophysiology, growth, and yield of mung bean varieties in the southeastern US need to be assessed. A field experiment was conducted at the Agricultural Research and Education Center of Tennessee State University to investigate the effects of four varieties (OK2000, Berken, TSU-1, AAMU-1) and three planting densities (5, 10, and 15 cm spacing) on the ecophysiology and yield of mung bean. Results showed that the relative chlorophyll content, plant height, pod dry biomass, pod number, crop yield, and harvest index significantly varied among the varieties. Density only influenced transpiration, relative chlorophyll content, and plant dry biomass. OK2000 had 101.0% more pods per plant and a 42.4% higher harvest index and produced a 45.3% higher yield than other varieties, but no significant difference in yield was found among the other three varieties. This study demonstrated that the mung bean variety OK2000 with a high yield would be ideal for commercial production in the southeastern US.

Effects of Planting Density and Nitrogen Amount on Stalk Lodging-Resistance and Yield of Summer Maize in Sichuan Basin

[Objective] The experiment was conducted to explore the suitable planting density and nitrogen amount for summer maize in Sichuan Basin with the objective to provide technical reservation and scientific basis for high-yielding cultivation technique.[Method] A widely planted maize cultivar ＇Chengdan 30＇ was used as experimental material to study the effects of planting density and nitrogen amount on the stalk agronomic traits,stalk lodging-resistance mechanical characters,stalk breaking percentage and yield of maize.Experiment was arranged in a two-factor split plot design with three replicates.The planting density was the main factor with three density gradients（4.5×10^4,6.0×10^4 and 7.5×10^4 plants/hm^2） and the nitrogen amount was the second factor with two different levels of nitrogen content（300 and 375 kg/hm^2）.[Result] The stalk lodging-resistance and yield were affected by planting density significantly.The increase of planting density would result in an increase of internode length and decrease of internode diameter,dry matter weight of per unit stalk length,rind penetration strength and breaking resistance of 3rd and 4th basal internodes.When planting density increased from 6.0×10^4 plants/hm2 to 7.5×10^4 plants/hm^2,the stalk breaking percentage in the whole growing season increased by 17.17%,and the yield reduced by 17.58%.The interaction between planting density and nitrogen amount affected the stalk breaking percentage in the whole growing season and yield significantly.The treatment with planting density of 6.0×104 plants/hm^2 and nitrogen amount of 375 kg/hm^2 of pure N was an optimal combination,which may not only control the stalk breaking percentage of whole growing stage effectively,but also could obtain an optimum grain yield.[Conclusion] In Sichuan Basin,the appropriate planting density and nitrogen amount for summer maize were 6.0×10^4 plants/hm^2 and 375 kg/hm^2.

Effects of Planting Density, Duration of Disclosing Plastic Film and Nitrogen Fertilization on the Growth Dynamics of Rapeseed under No-tillage Cultivation

[ Objective] This study was to understend the optimized combination of planting density, duration of disclosing plastic film and nitrogen fertilization under no-tillage cultivation. [ Method] Quadratic polynomial regression and saturated D-optimal design were employed to investigate the effects of planting density, duration of disclosing plastic film and nitrogen fertilization on the dynamics growth of rapeseed under no-tillage cultivation.[ Result] Within the experimental range, the growth dynamics of no-tillage cultivated rapeseed assumed a rise-fall tend. For the effects to the growth dynamics of no-tillage cultivated rapeseed, nitrogen application amount was higher than planting density and duration of disclosing plastic film. The interaction effect between planting density and duration of disclosing plastic film was higher than that between nitrogen application amount and planting density, and between nitrogen application amount and duration of disclosing plastic film. [ Conclusion] The optimized combination of these factors for dynamic growth of rapeseed under no-tillage cultivation was determined to be： planting density of per hectare 154 925 individuals, duration of disclosing plastic film of 110 d, nitrogen application amount of 315 kg/hm^2.

Suitable Date of Seeding, Planting Density and Water Use Efficiency for Propagation of Stock Seed Potato in Mountainous Region of Southwest Sichuan

[Objective] The experiment was conducted to study suitable date of seed- ing and density of spring potato at the stock breeding base in Ebian County at an elevation of 1 200 to 1 500 m. [Methods] Virus-free Potato ＂Chuanyu 13＂ was used as material to study the effects of date of seeding and density on growing period, germination rate, yield and water use efficiency of spring potato in the field. [Result] With the postponement of date of seeding, the days from sowing to germination shortened, while the germination rate, the number of tubers per plant, the number of middle and small tubers in a group, yield and water use efficiency all increased. Planting density had no effects on the days from sowing to germination and the ger- mination rate, while the number of tubers per ptant, the number of middle and small tubers in a group, yield and water use efficiency increased significantly along with the increasing planting density. [Conclusion] At an elevation of 1 200 m to 1 250 m in Ebian County, the suitable date of seeding for potato was from February 9 to March 1, and the suitable planting density was 12×10^4 plants per hm^2, however, in the optimum planting density has not been found so that it needs further research,

Effects of Genotype and Planting Density on Agronomic Traits and Storage Root of Sweetpotato

The effects ol different genotypes and planting densities on main agronomic traits, storage root traits and yield were studied with 6 high-quality sweetpotato varieties as study objects by 2-factor completely random design. The results showed that there were significant differences in stem diameter, length of the longest vine and top/root （T/R） between different genotypes, T/R differed significantly under dif- ferent planting densities, and number of basal branches decreased with planting density increasing. Genotype and genotype x density showed significant or very sig- nificant effects on fresh root yield per plant, dry matter content and fresh root yield per hectare, fresh root yield per plant gradually decreased with planting density in- creasing, while fresh root yield per hectare increased with planting density increas- ing. Numbers of storage roots in different sizes of the 6 sweetpotato cultivars all exhibited an order of number of large-sized storage roots〈number of medium-sized storage roots〈small-sized storage root; and there were very significant differences in ratio of large-sized storage roots between different genotypes. The number of large- sized storage roots, ratio of large-sized storage roots and number of commercial storage roots deceased with planting density increasing, while there were no signifi- cant differences in number of medium-sized storage roots, number of small-sized storage roots, ratio of medium-sized storage roots and ratio of small-sized storage roots between different densities. Correlation analysis showed that there was signifi- cant positive correlation between number of basal branches and fresh root yield per plant; dry matter content in storage roots was in significant positive correlation with stem diameter, and in significant negative correlation with length of the longest vine; fresh root yield per hectare was in significant positive correlation with fresh root yield per plant, and in very significant negative correlation with dry matter content; and ratio of large-sized storage roots was in very significant positive correlation with number of large-sized storage root and fresh root yield per plant, and in very sig- nificant negative correlation with ratio of medium-sized storage roots and ratio of small-sized storage roots. This experiment showed that under the planting density of 7.5×104 plants/hm2, the 6 sweetpotato cultivars all reached the highest numbers of commercial storage roots and fresh root yields per hectare.

Effects of Planting Density and Row Spacing on Grass Yield of Forage Sweet Sorghum(Sorghum bicolor [L.]Moench)

[Objective] The aim was to explore high-yielding cultivation techniques for forage sweet sorghum. [Method[ The effects of planting density and row spacing on plant productivity and grass yield of forage sweet sorghum （Sorghum bicolor （L.） Moench） were compared using split-plot design and LSD method of IBMSPSSStatis- ticsv22. [Result]The planting density and row spacing had important influence on the plant productivity and yield of forage sweet sorghum. The optimum planting density- row spacing combination for plant productivity of forage sweet sorghum was A1B,, i. e., planting density of 75 000 plants/hm2 and row spacing of 40 cm, and the opti- mum combination for yield of forage sweet sorghum was A2B,, i.e., planting density of 225 000 plants/hm2 and row spacing of 40 cm. [Conclusion] This study will pro- vide theoretical basis and technical support for the production practice of forage sweet sorghum.

Planting density affected biomass and grain yield of maize for seed production in an arid region of Northwest China

Field experiments were conducted from 2012 to 2015 in an arid region of Northwest China to investigate the effects of planting density on plant growth, yield, and water use efficiency（WUE） of maize for seed production. Five planting densities of 6.75, 8.25, 9.75, 11.25 and 12.75 plants/m^2 were conducted in 2012, and a planting density of 14.25 plants/m^2 was added from 2013 to 2015. Through comparison with the Aqua Crop yield model, a modified model was developed to estimate the biomass accumulation and yield under different planting densities using adjustment coefficient for normalized biomass water productivity and harvest index. It was found that the modified yield model had a better performance and could generate results with higher determination coefficient and lower error. The results indicated that higher planting density increased the leaf area index and biomass accumulation, but decreased the biomass accumulation per plant. The total yield increased rapidly as planting density increased to 11.25 plants/m^2, but only a slight increase was observed when the density was greater than 11.25 plants/m^2. The WUE also reached the maximum when planting density was 11.25 plants/m^2, which was the recommended planting density of maize for seed production in Northwest China.

Effect of planting density on plant growth and camptothecin content of Camptotheca acuminata seedlings

C. acuminata seedlings cultivated in greenhouse were transplanted into the fields with 5 designed planting densities (11, 16, 25,44 and 100 plants·m^-2) in May of 2004 and were harvested in the middle of September of 2004. The seedling growth indexes including plant height and crown width, biomass allocation, camptothecin (CPT) content and CPT yield of different organs (young leaf, old leaf, stem,and root) were studied. For the 5 selected planting densities, the plant biomass, height, crown width, and total leaf area of C. acuminata seedlings all showed highest values at the planting density of 25 plants ·m^-2. CPT content in young leaves was higher than that in other organs of seedlings and presented an obvious change with the variation of planting densities and with the highest value at density of 100plants·m-2, while for other organs no significant variation in CPT content was found with change of planting density. The accumulation of CPT was enhanced significantly at the planting density of 25 plants·m^-2. It is concluded that for the purpose to get raw materials with more CPT from C. acuminata, the optimal planting density of C. acuminata seedlings should be designed as 25 plants·m^-2.

Root characteristics and yield of rice as affected by the cultivation pattern of strong seedlings with increased planting density and reduced nitrogen application

To address the relationships between the amount of nitrogen fertilizer application and the yield of double cropping rice systems,we investigated the effects of a cultivation pattern of strong seedlings with increased planting density and reduced nitrogen application(SDN)on the morphological and physiological characteristics of double cropping rice.Our results indicated that the effects of SDN on the morphological characteristics of the single plant roots of double cropping rice were not significant,but the morphological characteristics of the population roots were largely different.Specifically,SDN significantly increased the morphological indexes of the root population such as root fresh weight,root volume,root number,root length and root dry weight.The effects of SDN on the total root absorption areas and root active absorption areas of the single plants were non-significant,but it dramatically enhanced the total root absorption areas and root active absorption areas of the plant population during the tillering,heading and mature stages.In addition,SDN significantly increased the root bleeding intensity and elevated the soluble sugar and free amino acid contents of root bleeding sap.Compared to the traditional cultivation pattern(CK),SDN significantly increased root bleeding intensity at the heading stage by 4.37 and 8.90% for early and late rice,respectively.Meanwhile,SDN profoundly enhanced the soluble sugar contents of root bleeding sap by 12.85 and 10.41% for early and late rice,respectively.In addition,SDN also significantly enhanced free amino acid content of root bleeding sap by 43.25% for early rice and by 37.50% for late rice systems compared to CK.Furthermore,SDN increased the actual yield of double cropping rice mainly due to the higher effective panicle number and the larger seedsetting rate.The actual yields of early rice under SDN were higher than CK by 9.37 and 5.98% in 2016 and 2017,and the actual yields of late rice under SDN were higher than CK by 0.20 and 1.41% in 2016 and 2017,respectively.Correlation analysis indicated that the significant positive correlations were observed between the majority of the root indexes and the actual yield across the four different growth stages.

Effects of Increased Planting Density with ReducedNitrogen Application on Yield Formation and NitrogenUtilization of Autumn Maize

With the change of cropping system in the middle reaches of the Yangtze River,the planting area of autumn maize is gradually increasing.However,the cultivation techniques are still under improvement for higher yield and nitrogen efficiency of autumn maize.Increase in planting density with reduced nitrogen fertilizer application is one of the important paths to achieve high yield and high nitrogen utilization efficiency.Meanwhile,the effect needs to be verified for autumn maize.The semi-compact autumn maize variety Qinyu 58 was planted under different planting densities and nitrogen fertilizer amounts with the split plot design.Different nitrogen application rates were arranged in the main plots,including the conventional nitrogen application(N300,300 kg/hm^2),30%reduction from the conventional treatment(N210,210 kg/hm^2)and no nitrogen application(N0).Different planting densities were arranged in the sub-split plots,including the conventional planting density(D60,60000 plants/hm2),medium density(D78,78000 plants/hm^2)and high density(D93,93000 plants/hm2).The effects of nitrogen fertilizer,planting density and their interaction effects on canopy structure,dry matter accumulation,yield and nitrogen use efficiency of autumn maize were studied.The nitrogen application rate and planting density had obvious interaction effects on the yield formation of autumn maize.Compared with the conventional cultivation(N300D60),increasing the planting density with 30%reduction in nitrogen application(N210)can obviously increase the canopy light interception rate,LAI,dry matter accumulation and yield.However,there was no significant change in canopy light interception rate,LAI,dry matter accumulation,grain weight and yield between D93 and D78.Compared with N300D60,nitrogen translocation efficiency and nitrogen contribution proportion to grain nitrogen did not change significantly in autumn maize grown under N210 and D78 treatments,whereas nitrogen partial productivity,nitrogen agronomic efficiency and recovery and utilization efficiency of nitrogen fertilizer increased significantly.Moreover,high density(D93)planting at N210 plots significantly improved nitrogen transport efficiency and utilization efficiency in autumn maize.Therefore,the suitable planting density of the autumn maize variety Qinyu 58 in Hubei Province is recommended a value of 78000 plants/hm^2,with the nitrogen application rate of 210 kg/hm2,which can achieve the target of higher yield by increasing density and reducing nitrogen.

Genome-wide association study and metabolic pathway prediction of barrenness in maize as a response to high planting density

Increasing the planting density is one way to enhance grain production in maize.However,high planting density brings about growth and developmental defects such as barrenness,which is the major factor limiting grain yield.In this study,the barrenness was characterized in an association panel comprising 280 inbred lines under normal(67500 plants ha–1,ND)and high(120000 plants ha–1,HD)planting densities in 2017 and 2018.The population was genotyped using 776254 single nucleotide polymorphism(SNP)markers with criteria of minor allele frequency>5%and<20%missing data.A genome-wide association study(GWAS)was conducted for barrenness under ND and HD,as well as the barrenness ratio(HD/ND),by applying a Mixed Linear Model that controls both population structure and relative kinship(Q+K).In total,20 SNPs located in nine genes were significantly(P<6.44×10–8)associated with barrenness under the different planting densities.Among them,seven SNPs for barrenness at ND and HD were located in two genes,four of which were common under both ND and HD.In addition,13 SNPs for the barrenness ratio were located in seven genes.A complementary pathway analysis indicated that the metabolic pathways of amino acids,such as glutamate and arginine,and the mitogen-activated protein kinase(MAPK)signaling pathway might play important roles in tolerance to high planting density.These results provide insights into the genetic basis of high planting density tolerance and will facilitate high yield maize breeding.

Evidence of arrested silk growth in maize at high planting density using phenotypic and transcriptional analyses

Increasing the planting density is an effective way to increase the yield of maize(Zea mays L.),although it can also aggravate ovary apical abortion-induced bald tips of the ears,which might,in turn,reduce the yield.While the mechanism underlying the regulation of drought-related abortion in maize is well established,high planting density-related abortion in maize remains poorly understood.Therefore,the present study was designed to investigate the mechanism underlying the ovary apical abortion response to high density.This was achieved by evaluating the effects of four different plant densities(60000 plants ha^(–1)(60 k),90 k,120 k,and 150 k)on plant traits related to plant architecture,the plant ear,flowering time,and silk development in two inbred lines(Zheng58 and PH4CV)and two hybrid lines(Zhengdan958 and Xianyu335).The phenotypes of both inbred and hybrid plants were observed under different planting density treatments,and the high planting density was found to increase the phenotypic performance values of the evaluated traits.The anthesis–silking interval(ASI)was extended,and the amount of the silk extruded from husks was reduced upon increasing the planting density.Delayed silk emergence resulted in asynchronous flowering and ear bald tips.Observations of the silk cells revealed that the silk cells became smaller as planting density increased.The changes in transcript abundances in the silks involved the genes associated with expansive growth rather than carbon metabolism.These findings further our understanding of silk growth regulation under high planting density and provide a theoretical basis for further research on improving high planting density breeding in maize.

Effects of Planting Density and Cutting Time on Hay Yield and Nutritional Value of Forage Soybean HN389

Forage soybean is an important source of high protein forage.Variety screening and breeding not only can solve the adjustment of agricultural planting structure,but also can provide a large amount of high-protein forage material,and effectively solve the problem of a serious shortage of high-protein forage in herbivorous animal husbandry in China.In this study,the feeding-type soybean strain HN389 was selected as experimental material,with three planting densities of 270000,405000 and 540000 plants•hm^(-2) and three cutting periods of the initial pod stage(R1),the initial grain stage(R2)and the early mature stage(R3)were set to determine the yield and feeding quality,in order to obtain the best planting density and harvest time of the variety.The results showed that in forage soybean strain HN389 at the R1 and R2 stages,plant height increased with increasing planting densities,while fresh and dry weight per plant decreased with increasing planting densities,and there was no significant difference at the R3 stage.The yield of hay at the R1,R2 and R3 stages increased firstly and then decreased with the increase of planting densities,and the yield per hectare was R3>R2>R1.The order of contents of crude protein(CP),neutral detergent fibers(NDF)and acid detergent fiber(ADF)in feeding quality of HN389 were R2>R1>R3,and ether extract(EE)content order was R3>R1>R2,and there was no significant difference among different groups.Two principal components were extracted from five forage indexes including CP,NDF,ADF,EE and fresh grass yield by principal component analysis.The cumulative contribution rate of principal components 1 and 2 was 90.053%,and their characteristic values were 3.617 and 0.885,respectively.After a comprehensive evaluation,harvested at the R3 stage and the density was 405000 plants•hm^(-2),HN389 had the highest comprehensive score of 0.344,yield of 38035.53 kg•hm^(-2),CP,NDF,ADF and EE contents of 17.61%,17.61%,21.54%and 3.81%,respectively.

Effect of Row Space and Planting Density on Yield of Miandan No.12

Effect of row space and planting density on yield of Miandan No.12 was studied. The test included four row spaces and two planting densities. Specifically, four row spaces were 50, 67, 83 and 100 cm and two planting densities were 42 000 and 48 000 plant/hm2. The results showed that Miandan No.12 reached the highest yield when row space was 50 cm and planting density was 48 000 plantJhm2 and Miandan No.12 got the lowest yield when row space was 100 cm and planting density was 42 000 plants/hm2.

Effect of Planting Density on Physiological Indexes, Agronomic Traits and Yield of Buckwheat ( Fagopyrum esculentum Moench.)

Ningqiao 1 was selected as the material to study the effects of planting density on physiological indices,agronomic traits and yield of buckwheat.The results showed that high density resulted in decreases of chlorophyll content,soluble protein content and activity of SOD,POD and CAT,and acceleration of MDA accumulation under drought conditions.Low density could effectively improve the grain number per plant,grain weight per plant,1000-grain weight and yield in drought conditions.

Effect of Fertilizing Amount and Planting Density on Yield and Qual-ity of Strong-gluten Wheat Taishan 27

To get the cultivation pattern featured by improved varieties and fine methods for strong-gluten and high-yielding wheat variety Taishan 27,this paper used Taishan 27 as material to study the effect of fertilizing amount and planting density on yield and quality of material.The results showed that Taishan 27 had high yield under fertilizing amount of 225 kg/ha pure nitrogen and planting density of 240 × 104-300× 10~4/ha; the yield was lowest under fertilizing amount of 300 kg/ha pure nitrogen and planting density of 360 × 10~4/ha. The suitable planting density for Taishan 27 was 240 × 104-300 × 10~4/ha,and the fertilizing amount of nitrogen should be based on different soil fertility conditions to avoid water and fertilizer stress and improve yield.

Effects of Planting Density of Quinoa on Agronomic Characters and Yield in Chengde

[Objectives]To study the optimum sowing density of quinoa in Chengde region.[Methods]Yanli No.2 cultivated by Institute of Millet Crops,Hebei Academy of Agriculture and Forestry Sciences was taken as test material.In Chengde region,single-factor density test design was used to study the effects of sowing on agronomic characters and yield of quinoa.[Results]Quinoa had the highest comprehensive yield when row spacing was 30 cm and plant spacing was 25 cm.[Conclusions]The research could provide theoretical basis for quinoa planting in Chengde region.

Effects of Planting Density and Row Spacing on Plant Productivity of Autumn Forage Sweet Sorghum in Hebei Province

[ Objective] This study was conducted to investigate the relationship between each of planting density and row spacing and plant productivity of forage sweet sorghum planted in autumn idle land. [ Methods] Using split-plot experiment design experiment method and LSD method of IBM. SPSS. Statistics. v22 statistics software, the effects of planting density and row spacing on plant productivity of forage sweet sorghum planted in autumn idle land were compared. [ Result] The results showed that the planting density and row spacing had important influences on plant productivity of forage sweet sorghum planted in autumn idle land. Moreover, the optimal combination of plant productivity for A1B4 , i. e. ,under the combination of the planting density of 7.5 × 10^4 plants/hm^2 and the row spacing of 40 cm, the fresh weight and dry weight per plant were 654.37 and 147.11 g/plant, respectively. [ Conclusion ] The results provided a theoretical basis for the production of forage sweet sorghum in autumn idle land.