Plant Nutrient Solution Detection System Based on ZigBee Wireless Technology

Based on the limitations of traditional plant nutrient solution detection, a ZigBee plant nutrient solution detection system based on CC2530 was developed. This system uses CC2530 as the main control chip, DS18B20 as the temperature sensor for temperature acquisition, PH electrode sensor for PH value acquisition. The experiment shows that this wireless control system equipped with temperature and pH detection sensor collects and samples the main nutrient solution parameters through the main controller, performs wireless communication transmission and terminal communication, and realizes the intelligent detection of plant nutrient solution parameters. This technique of applying wireless sensor network technology to plant factories greatly improves the reliability and stability of the nutrient monitoring system.

Effect of Nutrient Management and Planting Geometry on Productivity of Hybrid Rice (<i>Oryza sativa</i>L.) Cultivars

Field experiments were conducted during the wet seasons of 2006 and 2007 at the Agricultural Experimental Farm of the Indian Statistical Institute, Giridih, a part of eastern plateau region of India. The study was designed to investigate the effect of planting geometry and nutrient management practices on productivity of two hybrid rice cultivars. Split-plot design with three replications was adopted to carry out the experiment by allocating combinations of treatments of planting geometry and rice cultivar in main-plots and nutrient management treatments in sub-plots. “CNRH-3” rice proved its efficiency in terms of grain yield that was also reflected in yield attributing characters such as number of productive tillers, number of grains per panicle, length of panicle, panicle weight, test weight and harvest index. Higher rice grain yield was registered when the cultivars grown in 20 cm × 20 cm planting geometry. Rice cultivars grown with the application of inorganic fertilizers alone produced maximum grain yield and also recorded higher values of ancillary characters. The maximum amount of N, P and K was taken up by the “CNRH-3” rice, whereas maximum residual soil fertility was recorded in “Pro Agro 6201” rice. Maximum N, P and K uptake values were recorded in 20 cm × 20 cm crop geometry and inorganic fertilizers treatment.

Interaction effect of nitrogen form and planting density on plant growth and nutrient uptake in maize seedlings

High planting density is essential to increasing maize grain yield.However,single plants suffer from insufficient light under high planting density.Ammonium(NH_4^+)assimilation consumes less energy converted from radiation than nitrateIt is hypothesized that a mixed NO_3~–/NH_4^+supply is more important to improving plant growth and population productivity under high vs.low planting density.Maize plants were grown under hydroponic conditions at two planting densities(low density:only).A significant interaction effect was found between planting density and N form on plant biomass.Compared to nitrate only,75/25NO_3~–/NH_4^+increased per-plant biomass by 44%under low density,but by 81%under high density.Treatment with 75/25NO_3~–/NH_4^+increased plant ATP,photosynthetic rate,and carbon amount per plant by 31,7,and 44%under low density,respectively,but by 51,23,and 95%under high density.Accordingly,carbon level per plant under 75/25NO_3~–/NH_4^+was improved,which increased leaf area,specific leaf weight and total root length,especially for high planting density,increased by 57,17 and 63%,respectively.Furthermore,under low density,75/25NO_3~–/NH_4^+increased nitrogen uptake rate,while under high density,75/25NO_3~–/NH_4^+increased nitrogen,phosphorus,copper and iron uptake rates.By increasing energy use efficiency,an optimum NO_3~–/NH_4^+ratio can improve plant growth and nutrient uptake efficiency,especially under high planting density.In summary,an appropriate supply of NH_4^+in addition to nitrate can greatly improve plant growth and promote population productivity of maize under high planting density,and therefore a mixed N form is recommended for high-yielding maize management in the field.

Effects of Spraying Plant Nutrient, Slaked Lime and Pokeberry Root Powder on Cadmium Reduction in Rice

The pot experiment was carried out in this study to further explore the impact of plant nutrient, slaked lime, pokeberry root powder on cadmium （Cd） absorption by rice, and to screen practical agronomic measures which could reduce the accumulation of cadmium. In the control treatment nothing but water was sprayed into rice, while in other treatments, plant nutrient, slaked lime and pokeberry root powder were sprayed on rice at the tillering stage, the heading stage and the dough stage, respectively. The plant samples and soil samples were collected after the harvest and then analyzed on aimed indexes. The results showed that Cd contents in rice plants were significantly decreased, total Cd contents in brown rice were significantly （P〈0.05） decreased after rice was sprayed with plant nutrient, slaked lime and pokeberry root powder at different growing stages. However, while rice was sprayed with the three materials all at the tillering stage, the heading stage and the dough stage, the total Cd contents in brown rice were decreased by a maximum reduction that was 53.4% to 57.5% below that of the control, which was signifcantly （P〈0.05） lower than other treatments. Meanwhile, the biggest reduction of Cd inrice sprayed with the three materials at the tillering stage was 19.6% to 35.1% below that of the control, which was signifcantly （P〈0.05） lower than other treatments. In conclusion, spraying plant nutrient, slaked lime and pokeberry root powder on rice at different growing stages could not only reduce the absorption accumulation of Cd by root system, but also change the activities of rice and physical and chemical properties of soil, and then inhibit the absorption of Cd by the root system and the transfer of Cd in the rice plant. Therefore, the multiple factors may be the main causes of reducing Cd contents in the brown rice when the three materials are sprayed on rice at different growing stages.

Effects of Planting Methods on Root Yield and Nutrient Removal of Five Cassava Cultivars Planted in Late Rainy Season in Northeastern Thailand

The objectives of this study were to evaluate growth, yield and nutrients removal of five cassava cultivars planted by different planting methods in late rainy season of northeastern Thailand. A split plot design was used in this study. The planting methods (vertical and horizontal) were assigned as main-plots. Cassava cultivars (Rayong-7, Rayong-11, Rayong-72, Huaybong-80 and E-dum) were assigned as sub-plots with four replications. Results showed that vertical planting gave significantly higher fresh storage root yield than those of horizontal planting, across five cassava cultivars. The cultivar Rayong-7 produced maximum fresh storage root yield across two planting methods, but not significantly different from Rayong 11, Huaybong 80 and Edum cultivars. Irrespective of nutrient removal, N, P and K removed ranges from 2.9 - 3.6, 0.8 - 1.3 and 5.3 - 7.9 kg per ton fresh root weight, respectively depending on cassava cultivar. The cultivar Rayong-7 removed the highest quantities of N, and the cultivar Rayong-11 removed maximum of P and K in the present study. Regardless of nutrient removal at different plant parts;N, P and K removed maximum quantities in leaf, stem and storage root, respectively. Planting method had no significant effect on N and P removal, but significant effect on K removal. The vertical planting removed K higher than those of horizontal planting.

Macro and Micro Nutrient Supply to Soil and Plants from Sugar Mill Mud

The effects of sugar mill mud application on the availability of nutrients for plant uptake were investigated. Mill mud generated from conventional sugar mill operations was applied in three different rates and a leafy vegetable, locally called “PuiShak” or Indian spinach (Basellarubra L.) was grown for 60 days as a test crop in a pot culture experiment. Crop yield and essential nutrients like N, P, K and Zn uptake concentration was determined to come up with an inference that higher doses of mill mud application impose better effect on root and shoot uptake of these elements. A little infraction was observed for nitrogen uptake by plants for the maximum dose.

The Determination of Plant Nutrients Taken from Soil of Black Cumin （Nigella sativa L.） as Traditional Spice

This study was carried out under Cumra-Konya conditions, in 2007, for the determination of consumption of the plant nutrients from soil by black cumin plants. The soil samples were taken before sowing and after harvest from the field that was sown black cumin and determined the rate of major and minor plant nutrients. For this reason, soil samples were taken from the depth of 30 cm as 2-3 kg and analyzed. The harvested black cumin yielded approximately 1,350 kg/ha seed. The analyses made in soil samples were pH, salinity, organic matter and lime, P, K, Ca, Mg, Na, Cu, Fe, Zn and Mn. According to the results, the parcel soil has not salt problem, and is little alkaline, more limy and little humic, good for phosphorus and very rich with respect potassium before sowing. At the same time, the parcel soil samples after harvest were little saline, little alkaline, more limy, poor humic, good for phosphorus and very rich with respect potassium.

GIS-Mapping of Soil Available Plant Nutrients (Potentiality, Gradient, Anisotropy)

The research was elaborated in Kafr El-Dawar area (Egypt northern region) to study the availability of the soil plant nutrients. The research introduced three parameters to comprehensively and carefully describe the availability of the soil plant nutrients: potentiality, gradient and anisotropy. Potentiality defines the categories of soil ability to supply plant nutrients;meanwhile gradient expresses the increasing rate of the availability of the soil plant nutrients. The gradient anisotropy refers to the directions or orientation of the increasing rate of the availability of the soil plant nutrients. The introduced parameters enabled to spatially study the availability of the soil plant nutrients. Analytical data, of soil available phosphorus (P), indicated that P ranged from 0.2 ppm to 11.4 ppm to locate all studied soil samples into the low class of the soil nutritional P ability. This was not the case of available potassium (K), where the soil samples were distributed into three available K soil categories: medium, high, and very high. GIS map of soil P nutritional potentiality for plant (potato), displayed the soil studied area in one category, as low P soil nutritional potentiality to coincide with the analytical data classification. Contrary, the K map classified the soil studied area into three categories of soil K nutritional potentiality: medium, high and excessive. This obviously referred that the individual determination of soil K nutritional potentiality is misleading for interpretation of soil tests because it does care of the spatial distribution of soil available K. Nearly, all soil samples had high available micronutrients that they were located in the high category in both classification of analytical data and GIS maps. GIS gradient maps of the soil available plant nutrients referred that the soil plant nutrients, exception of K, had two gradients: non increasing-slight increasing and build up. Gradient of soil available potassium was classified into four classes: non increasing-slight increasing, build up, moderately increasing and hike. Regardless potassium case, the non increasing-slight increasing gradient class dominated the others. GIS maps of anisotropy soil availability of macronutrients (P and K) generally showed that their gradients mainly increased in two directions: north and south. The incasing directions of soil availability of micronutrients coincided with that of the macronutrients.

Optimizing Plant Geometry and Nutrient Management for Grain Yield and Economics in Irrigated Greengram

Greengram (Vigna radiata L.) is important pulse crop in India. The yield and economics were in-creased by optimization of plant geometry and nutrient management under irrigated condition. The field experiment was conducted during Rabi season of November 2013 to January 2014 at Tamil Nadu Agricultural University, Agricultural College and Research Institute, Killikulam. An experiment was laid out in randomised block design and replicated thrice and the test variety of the crop greengram (CO 6) was used. The plant geometry of 30 × 30 cm, 25 × 25 cm and 30 × 10 cm was adopted. The Soil Test Crop Response (STCR) based fertilizer application, RDF, FYM and ZnSO4 was applied in soil as basal. The foliar spray of Pulse Wonder and Pink-pigmented facultative methylotrophs (PPFM) spray was done at one week after flowering and 1% KNO3 at 50 per cent flowering. Adoption of planting geometry of 30 × 30 cm, application of RDF, 12.5 t of FYM and 25 kg ZnSO4 as basal and foliar spraying of 1% KNO3 at 50 per cent flowering recorded higher dry matter production of 2865 kg·ha-1 and yield attributes viz., number of pod clusters plant-1 (10.34), number of pods plant-1 (53.40), number of seeds pod-1 (13.23), pod length (8.77 cm) and seed test weight (3.42 g). Higher grain yield of 1775 kg·ha-1, haulm yield (2920 kg·ha-1), harvest index (0.38), net return (57,806 Rs·ha-1) and B:C ratio (2.43) were associated with the treatment comprising of 30 × 30 cm spacing, application of RDF, 12.5 t of FYM and 25 kg ZnSO4 as basal and foliar spraying of 1% KNO3 at 50 per cent flowering.

Nutrients of Topsoil for Sugarcane Planting in Xinping County of Yunnan Province

To provide reference for fertilizer application of sugarcane planting in Xinping County,this paper analyzed nutrient content of topsoil according to the nutrient indicators established in the Second Soil Census. The results show that 51. 76% soil in sugarcane planting area of Xinping County is faintly acid,50. 88% soil has relatively low organic matter,45. 88% soil lacks alkali-hydrolyzable nitrogen( N),26. 47% soil lacks phosphorus( P),50. 29% soil lacks potassium( K),37. 14% soil lacks sulfur( S),12. 86% soil lacks magnesium( Mg),10% soil lacks manganese( Mn),and 31. 43% soil lacks zinc( Zn). In the sugarcane production,it is required to pay attention to increase of application of organic fertilizer,to foster soil fertility,supplement boron fertilizer,to keep balance of soil nutrients.

Effects of Planting Methods and Seed Density on Vegetable Yield and Nutrient Composition of <i>Solanum macrocarpon</i>and <i>Solanum scabrum</i>in Southwest Nigeria

Two field studies were carried out using Solanum macrocarpon and Solanum scabrum to investigate the effects of planting methods and seed density required for optimum biomass yield and nutrient content in southwest Nigeria. Two planting methods (drilling and broadcasting), and two seed densities (4 and 8 table spoon full) were investigated as a 2×2×3 factorial experiment in randomized complete block design and replicated three times. Four seed spoons gave 25.78 kg seeds ha-1 for S. macrocarpon and 20.67 kg·seeds·ha-1 for S. scabrum. Significant highest S. macrocarpon shoots (2.75 kg·m-2) and Ca, K, Fe and Zn contents and S. scabrum (2.95 kg·m-2) and Zn content, were obtained with drilling and four spoons of seeds compared with broadcasting and 8 spoons of seeds. This treatment gave average values for N, P, K, Mg, Ca, Na, Fe, Zn, Mn, Cu, Ca/P and Na/K ratio were 2.79%, 0.03%, 3.37%, 1.64%, 0.02%, 300 mg·kg-1, 100 mg·kg-1, 300 mg·kg-1, 8 mg·kg-1, 1.22 and 0.008 for S. macrocarpon and 2.05%, 0.27%, 5.81%, 3.27%, 2.91%, 0.09%, 280 mg·kg-1, 52.99 mg·kg-1, 359.35 mg·kg-1 and 22.42 mg·kg-1, 11.63 and 0.016 for S. scabrum. It was concluded that planting in drilling made weeding, fertilizer application, irrigation and harvesting more effective rather than by broadcasting, and four spoons of seeds per 9 m-2 produced deep green and broader leaves and balanced nutrient contents than eight spoons of seeds.

Effect of Plant Ash on Nutrient Quality and Antioxidant Activity of African Yam Bean Seed Porridge in Relation to Cooking Time

The present study aimed to investigate the nutrient quality, antioxidant activity and sensory acceptability of hard-to-cook African yam bean (AYB) seeds cooked for 5 h (control) and for 2 h with plant ash. The plant ash were unripe plantain peel ash (UPA), corn cob ash (CCA) and UPA and CCA mixture. Standard methods of Association of Official Analytical Chemists (AOAC) were used for the proximate and mineral analysis, DPPH, ABTS and FRAP assays were used to investigate the antioxidant activity. A completely randomized design with one way analysis of variance (ANOVA) was used for data analysis. The results showed that cooking of AYB seeds for 2 h with 8 g/100mL plant ash solution improved the nutrient contents, antioxidant activity and sensory scores of the porridge. Higher values of proteins, ash and energy were obtained in 8 g/100mL UPA/CCA and in 8 g/100mL CCA additives. However, moisture, fat and fibre contents were not affected by plant ash additives and were higher in 5 h cooked porridge. Cooking with 8 g/100mL plant ash solution for 2 h significantly increased mineral elements in the porridge. Phenolic compounds (total polyphenols and flavonoids), and antioxidant activity (DPPH, ABTS and FRAP) showed higher values with plant ash additives. This study reveals that addition of plant ash did not only reduce the cooking time of AYB seed by 60%, but also improved the nutrient quality, antioxidant activity and sensory acceptability.

Purification of Several Salt Marsh Plants to the Coastal Wetlands in the Estuary of Yellow River

The paper compared the differences between above ground and underground biomass of four types of plants.The heavy metals(Cu,Zn,Cd,Cr,Pb,As,Hg)and nutrients(TN,TP)content in tissues of four maturity plants were detected,and their enrichment coefficient and transfer coefficient were calculated.The results showed that Suaeda salsa had the largest concentrated capacity on Cu,Zn,Pb,As and Phragmites australis was larger on the Cd,Hg than other plants.Considering the purification of four plants,the effect on the restoration of heavy metal pollution was better if we harvested Phragmites australis and Suaeda salsa.Four plants had a larger difference in absorption capacity of nitrogen and smaller absorption of phosphorus.Phosphorus uptake was significantly smaller than nitrogen.Harvesting Phragmites australis and Suaeda salsa can reduce total nitrogen and phosphorus content of the wetland,while harvesting Spartina alterniflora and Typha orientalis can reduce total phosphorus content.

Effects of Microbial Inoculants on Nutrient Availability and Rice Yield

Under field conditions, an experiment was conducted to study the effects of ammonification bacteria, potassium bacteria and phosphorus bacteria on nutrient availability in soil and yield of rice in the cold region of China and compared to the conventional fertilization. Results showed that DF1P2 treatment （ammonifiers 1.5× 108 cfu· m2, phosphorus bacteria 1.5× 108 cfu. m2, and potassium bacteria 1.5× 108 cfu· m2） increased available nutrient concentrations in soil, increased the concentrations of N, P, and K in plant organs and increased the rice yield and was the most significantly among all the treatments. This treatment could be recommended as the best suitable biological fertilizer application rate for the rice production in the cold region of China.

Plant Traits for Phytoremediation in the Tropics

Water is a limited and valuable resource.Singapore has four national sources of water supply,one of which is natural precipitation.Pollutants collected in stormwater runoff are deposited into drainage systems and reservoirs.Major nutrient pollutants found in local stormwater runoff include nitrate and phosphate,which may cause eutrophication.Bioretention systems are efficient in removing these pollutants in the presence of plants.This paper discusses plant traits that can enhance the phytoremediation of nutrient pollutants in stormwater runoff for application in bioretention systems.The plant species studied showed variations in chlorophyll florescence,leaf greenness,biomass production,and nitrate and phosphate removal.In general,dry biomass was moderately correlated to nitrate and phosphate removal(r=0.339–0.501).Root,leaf,and total dry biomass of the native tree species showed a moderate to strong correlation with nitrate removal(r=0.811,0.657,and 0.727,respectively).Leaf dry biomass of fastgrowing plants also showed a moderate to strong relationship with the removal of both pollutants(r=0.707 and 0.609,respectively).Root dry biomass of slow-growing plants showed a strong relationship with phosphate removal(r=0.707),but the correlation was weaker for nitrate removal(r=0.557).These results are valuable for choosing plants for application in bioretention systems.

Leaf N and P stoichiometry of 57 plant species in the Karamori Mountain Ungulate Nature Reserve,Xinjiang,China

Nitrogen （N） and phosphorus （P） are the major nutrients that constrain plant growth and development, as well as the structure and function of ecosystems. Hence, leaf N and P patterns can contribute to a deep understanding of plant nutrient status, nutrient limitation type of ecosystems, plant life-history strategy and differentiation of functional groups. However, the status and pattern of leaf N and P stoichiometry in N-deficiency desert ecosystems remain unclear. Under this context, the leaf samples from 57 plant species in the Karamori Mountain Ungulate Nature Reserve, eastern Junggar Desert, China were investigated and the patterns and interrelations of leaf N and P were comparatively analyzed. The results showed that the average leaf N concentration, P concentration, and N：P ratio were 30.81 mg/g, 1.77 mg/g and 17.72, respectively. This study found that the leaf N concentration and N：P ratio were significantly higher than those of studies conducted at global, national and regional scales; however, the leaf P concentration was at moderate level. Leaf N concentration was allometrically correlated with leaf P and N：P ratio across all species. Leaf N, P concentrations and N：P ratio differed to a certain extent among plant functional groups. C4 plants and shrubs, particularly shrubs with assimilative branches, showed an obviously lower P concentration than those of C3 plants, herbs and shrubs without assimilative branches. Shrubs with assimilative branches also had lower N concentration. Fabaceae plants had the highest leaf N, P concentrations （as well as Asteraceae） and N：P ratio; other families had a similar N, P-stoichiometry. The soil in this study was characterized by a lack of N （total N：P ratio was 0.605）, but had high N availability compared with P （i.e. the available N：P ratio was 1.86）. This might explain why plant leaves had high N concentration （leaf N：P ratio〉16）. In conclusion, the desert plants in the extreme environment in this study have formed their intrinsic and special stoichiometric characteristics in relation to their life-history strategy.

Responses of Plant Community and Soil Properties to Inter-Annual Precipitation Variability and Grazing Durations in a Desert Steppe in Inner Mongolia

Grazing can dramatically affect arid grassland communities that are very vulnerable to environmental changes due to its relatively short and sparse ground coverage, low biomass, sandy soil and inter-annual precipitation found in the desert steppe. The study investigates the effects of different grazing durations on vegetation and soil properties of a desert steppe community. The experiment was conducted in Xisu Banner in Inner Mongolia with ifve treatments：CG （continuous grazing）, 40UG （40 d ungrazed）, 50UG （50 d ungrazed）, 60UG （60 d ungrazed） and UG （ungrazed）. The biomass of both shrub and annual-biennial plant communities were signiifcantly decreased by CG. Continuous grazing and 40UG signiifcantly reduced the ANPP （aboveground net primary productivity） by the end of the three year study. 60UG treatment increased soil organic carbon （OC）, total nitrogen concentration （TN） and total phosphorus concentration （TP） concentrations and 50UG increased the TN and total phosphorus concentration （TK） concentrations, whereas CG, 40UG and 50UG decreased soil OC, TP and available phosphorus concentration （AP） concentrations. The perennial plant species of the desert steppe were generally tolerant for grazing. The annual-biennial plant species had large variability in ANPP because of the inter-annual precipitation. Our results highlight that inter-annual precipitation variations could strongly modify the community responses to grazing in arid ecosystems.

Variation of soil enzyme activity and microbial biomass in poplar plantations of different genotypes and stem spacings

To improve the productivity of poplar planta- tions, a field experiment of split-plot design with four tree spacings and three poplar clones was established, and four soil enzyme activities and microbial biomass were monitored in the trial. Soil enzyme activities, in most cases, were significantly higher in topsoil （0-10 cm） than in lower horizons （10-20 cm）. Soil cellulase, catalase and protease activities during the growing season were higher than during the non-growing season, while invertase activity followed the opposite trend. Soil invertase, cellulase and catalase activities varied by poplar clone but soil protease activity did not. Cellulase and protease activities in the plantation at 5 × 5 m spacing were significantly higher than in the other spacings. The highest catalase activity was recorded at 6 × 6 m spacing. At the same planting density, invertase activity was greater in square spacings than in rectangular spacings. Soil microbial biomass was also significantly affected by seedling spacing and poplar clone. The mean soil MBC was significantly lower in topsoil than in the lower horizon, while MBN showed the opposite pattern. Significantly positive correlations were observed among soil cellulase, protease and catalase activities （p 〈0.01）, whereas soil invertase activity was negatively and significantly correlated with cellulase, protease and catalase activities （p 〈 0.01）. Soil microbial biomass and enzyme activities were not correlated except for a significantly negative correlation between soil MBC and catalase activities. Variations in soil enzyme activity and microbial biomass in different poplar plantations suggest that genotype and planting spacing should be considered when modeling soil nutrient dynamics and managing for long-term site productivity.

Effects of Biochar Application on Soil Properties, Plant Biomass Production, and Soil Greenhouse Gas Emissions: A Mini-Review

Biochar has been applied extensively as a soil amendment over the past decades. This review summarizes the general findings of the impacts of biochar application on different aspects from soil physical, chemical, and microbial properties, to soil nutrient availabilities, plant growth, biomass production and yield, greenhouse gases (GHG) emissions, and soil carbon sequestration. Due to different biochar pyrolysis conditions, feedstock types, biochar application rates and methods, and potential interactions with other factors such as plant species and soil nutrient conditions, results from those studies are not inclusive. However, most studies reported positive effects of biochar application on soil physical and chemical properties, soil microbial activities, plant biomass and yield, and potential reductions of soil GHG emissions. A framework of biochar impacts is summarized, and possible mechanisms are discussed. Further research of biochar application in agriculture is called to verify the proposed mechanisms involved in biochar-soil-microbial-plant interactions for soil carbon sequestration and crop biomass and yield improvements.