P2O5 Ha-1 Research Articles

Influence of Silicon and Phosphorus on Yield and Nutrient Content of Wheat in Loamy Sand Soils of Sadarkrushinagar, Banaskantha, Gujarat, India

To investigate the influence of silicon and phosphorus application on yield and nutrient content of wheat, a field experiment was carried out at Agronomy Instructional Farm, Chimanbhai Patel College of Agriculture, Sardarkrushinagar Dantiwada Agricultural University, Sardarkrushinagar during Rabi season of 2020-2021. Experimental soil was loamy sand in texture with pH 7.01 and electrical conductivity 0.19 dSm-1. The soil was low in organic carbon (0.39%) and medium in available phosphorus (38.10 kg ha-1) and potassium (191.25 kg ha-1). Available silicon in soils was 60.75 mg kg-1. The experiment was dispersed as four levels of phosphorus (0, 30, 60 and 90 kg P2O5 ha-1) and four levels of silicon (0, 100, 200 and 300 kg Si ha-1) laid in randomized block design with factorial concept and replicated thrice. All the plots received a uniform recommended dose of nitrogen at 120 kg ha-1. Yield and nutrient content viz., nitrogen, phosphorus, potassium and silicon of grain and straw were noted. The results of experiment clearly indicated that the individual application of 60 kg ha-1 phosphorus and 100 kg ha-1 silicon recorded the significantly highest grain yield of 3808 and 3619 kg ha-1, respectively. With respect to phosphorus and silicon content in grain (0.36 and 1.64%) and straw ( 0.32 and 1.67%), individual application 60 and 90 kg P2O5 ha-1 and 100 kg Si ha-1 and 300 kg Si ha-1recorded maximum, respectively. As of interaction effect, significantly highest grain yield (4304 kg ha-1), and phosphorus content in grain (0.39%) was found with interaction effect of 60 kg P2O5 ha-1 with Si level at 100 kg ha-1. Whereas the significantly highest straw yield (6201 kg ha-1), silicon content in grain (1.82%) and straw (4.21%) was found with interaction of 90 kg P2O5 ha-1 with Si level at 100 kg ha-1and 90 kg P2O5 ha-1 with Si level at 200 kg ha-1. From the results of experimentation, it is clear that application of 60 kg P2O5 ha-1 along with 100 kg Si ha-1 could be better for increasing yield and nutrient content in wheat in loamy sand soils under North Gujarat Agro-climatic conditions.

Phosphate fertilization of Mesosetum chaseae in Roraima’s savannas

The objective of this work was to evaluate the effect of phosphate fertilization (0, 30, 60 and 120 kg of P2O5 ha-1) on forage production and morphogenetic and structural characteristics of Mesosetum chaseae under natural field conditions in the savannas of Roraima. Phosphate fertilization positively and significantly (P<0.05) affected green dry matter (GDM) production, absolute growth rate (AGR), number of tillers plant-1, number of leaves tiller-1 (NLT), average leaf size (ALS), leaf tiller area (LTA), appearance rates (LAR), expansion (LER) and leaf senescence rates. The maximum yields of GDM, AGR, LAR, LER, NLT, LTA and ALS were obtained with the application of 89.17; 112.7; 47.7; 51.9; 102.9; 101.8 and 94.8 kg of P2O5 ha-1, respectively. The efficiency of P utilization was inversely proportional to the P doses applied.

Agronomic performance and morphogenic and structural characteristics of Axonopus aureus pastures under phosphate fertilization levels in the Roraima’s savannas

The effect of phosphate fertilization (0, 30, 60 and 120 kg of P2O5 ha-1) on forage production and morphogenetic and structural characteristics of Axonopus aureus was evaluated under natural field conditions in the savannas of Roraima. Phosphate fertilization positively and significantly (P<0.05) affected green dry matter (GDM) production, absolute growth rate (AGR), number of tillers plant-1, number of leaves tiller-1 (NLT), average leaf size (ALS), leaf tiller area (LTA), appearance rates (LAR), expansion (LER) and leaf senescence rates. The maximum yields of GDM, AGR, LAR, LER, NLT, LTA and ALS were obtained with the application of 110.4; 108.5; 54.1; 83.5; 96.6; 59.8 and 90.6 kg of P2O5 ha-1, respectively. The efficiency of P utilization was inversely proportional to the P doses applied.

Effect of Nutrient Management and Crop Residue Incorporation on Phosphorus Uptake of Maize (Zea mays L) at Different Growth Stages

The uptake of phosphorus was found to increase with each successive increase in nitrogen level from 200 to 300 kg ha-1 and up to 60 kg ha-1 with increase in age of the crop with higher uptake at 300 kg N ha-1 and 60 kg P2O5 ha-1. Crop sown in N3P3 (300 kg N + 80 kg P2O5 ha-1) recorded significantly higher phosphorus uptake by grain. Higher nutrient uptake was recorded in F2 (125% of F1) and F4 (F2+ Kharif crop residue incorporation), while the sub plot F1 (Recommended dose of N and P2O5) and F3 (F1+ Kharif crop residue incorporation) recorded lower nutrient uptake during both the years. The uptake of phosphorus by maize increased with each successive increment of nitrogen and phosphorus but the trend is not consistent. The higher level of nutrients supplied through increased dose of nitrogen along with phosphorus is conducive for extensive root proliferation, to explore a greater volume of soil and absorb larger quantities of nutrients. Enhanced uptake of nutrients often tends to correlate positively with dry matter production and concentration of nutrients in the plant under higher level of nutrient supply. Residues of corn did not affect the P uptake and the nutrients released from corn residue is not a major contributor for subsequent corn nutrient uptake in sandy loam soils as is evidenced with highest nutrient uptake in the plots received with 125 % recommended dose either with or without residue incorporation.

Effect of phosphorus levels on nutrient availability, growth and yield of potato crop (Solanum tuberosum L.)

The experiment was conducted on potato (cv. Kufri Khyati) at the main experiment station, Department of Vegetable Science, Acharya Narendra Deva University of Agriculture and Technology, Narendra Nagar (Kumarganj), Ayodhya (U.P.) during the Rabi season of 2016-17. Seven treatments were arranged in randomized block design with four replications. The experimental findings showed that the use of RDF 100 kg P2O5 ha-1 was found better with respect to promotion of growth, yield and quality parameters of potato. The maximum value on growth characters were also recorded with RDF 100 kg P2O5 ha-1 in potato. It was found significantly superior over other treatments in almost all growth characters. The yield contributing characters such as the weight of A, B, C and D grade tubers per plot and the yield of tubers (q ha-1) were influenced significantly by using different levels of phosphorus. The maximum yield (388.79 q ha-1) was recorded with the application of RDF 100 kg P2O5 ha-1 in potato. It was found significantly superior over the rest of the treatments. An application of RDF 100 kg P2O5 ha-1 was found to be most effective for optimum growth: maximum tubers yield (388.79 q ha-1) and maximum net return Rs. 139062 as benefit cost ratio 1.47 on this dose of Phosphorus in the year’s investigation.

Effect of phosphorus and bio-inoculants on root nodules, nutrient uptake, quality and economics of summer mungbean [Vigna radiata (L.) Wilczek

A field experiment was conducted at Rajasthan College of Agriculture Udaipur, (MPUAT) (Rajasthan) during Summer season of 2016 to evaluate the effect of phosphorus and bio-inoculants on soil fertility and yield of Mungbean [Vigna radiata (L.) Wilczek] under factorial randomized block design with three replications and two factors likewise, four level of phosphorus Control (0 kg P2O5 ha-1) , 20, 40 and 60 kg P2O5 ha-1 and four level of bio-inoculants (control, PSB, Aspergillus awamori , PSB + Aspergillus awamori ) applied to the variety SML-668. The data were analyzed using standard statistical procedures. Results revealed that application of 40 kg P2O5 ha-1 significantly enhances number of total and effective nodules per plant flowering stage after 45 DAS, leaf area index, chlorophyll content, protein content in seed, as well as produces the higher net returns (62144 Rs /ha) and highest B:C ratio (3.86) which was statistically at par with 60 kg P2O5 /ha. Inoculation of mungbean seeds with PSB + Aspergillus awamori significantly increased number of total and effective nodules at flowering after 45 DAS, LAI, chlorophyll content, nutrient content, protein content in seed, and gave highest net return ₹63187 /ha as compared to control, PSB and Aspergillus awamori, whereas, B:C ratio of treatment PSB and Aspergillus awamori was highest 3.98 as compared to control.

Effect of Nitrogen and Phosphorus levels on growth and yield of direct-seeded rice (Oryza sativa L.) under Nagaland conditions

A field experiment was conducted entitled “Effect of nitrogen and phosphorus levels on growth and yield of direct seeded rice (Oryza sativa L.) under Nagaland condition” during the kharif period i.e., June-October 2018, in the experimental research farm of the School of Agricultural Sciences and Rural Development, Nagaland University. Nine treatments comprising three levels of N (0, 50, 100 kg N ha-1) and three levels of P (0, 40, 80 kg P2O5 ha-1) were used. The study revealed that N2 (100 kg N ha-1), P1 (40 kg P2O5 ha-1) and interaction treatment T8 (100 kg N: 40 kg P2O5) had performed significantly better as compared to other levels and combination treatments in terms of growth and yield in rice crop. Application of N and P levels significantly increased plant height (cm), number of tillers, crop growth rate (g g-1 day-1) and relative growth rate (g g-1 day-1). The highest grain yields (3687.96, 3687.96, 4442.42 kg ha-1) were recorded with N2, P1 and T8. Maximum straw yield was recorded with treatment levels of N2 (7394.96 kg ha-1), P2 (6531.29 kg ha-1) and T8 (8284.06 kg ha-1). The HI (%) was recorded highest with N2 (33.42%), interaction treatment T8 (35.59%) while P levels did not give any significant results.

Response of different phosphorus, sulphur and zinc levels on yield and economics of lentil cultivation in sub-humid region of Rajasthan

The experiment was conducted during rabi season of 2020-21 and 2021-22 at the Rajasthan College of Agriculture, MPUAT, Udaipur (Rajasthan). The experiment consisted of 18 treatments comprising different levels of phosphorus (three- 30,40 and 50 kg P2O5 ha-1), sulphur (three- 15, 20 and 25 kg S ha-1) and zinc (two- control and 0.5 % ZnSO4). The experiment was laid out in factorial randomized block design (FRBD) and replicated thrice. The results revealed that application of 50 kg P2O5 ha-1 recorded significantly higher biological yield, seed and haulm yield, net returns and benefit cost ratio. Among sulphur levels seed and haulm yield, biological yield, net returns and benefit cost ratio were higher under application of 25 kg S ha-1 and same results were found with foliar spray of 0.5 % ZnSO4 at 55 days after sowing. Thus, it can be concluded that application of 50 kg P2O5 ha-1 with 25 kg S ha-1 and 0.5 % ZnSO4 foliar spray at 55 DAS in lentil is productive as well as profitable.

Effects of Goat Manure, Biochar, and NPK Applications on Growth and Nutrient Concentrations of Lettuce

During the last decades, biochar (BC) gained increasing importance amongst scholars. Though, only a few studies explored the effects of the combined application of BC with manure on plant growth and nutrient concentrations. This study investigates the effects of separate and joint applications of goat manure (GM) and its derived BC on the growth and mineral element concentrations in lettuce. A completely random design was used in the field experiment. Two factors consisted of GM, BC at 5 Mg ha-1 and 10 Mg ha-1 combined with inorganic fertilizers [nitrogen, phosphorus, and potassium (NPK)] at 100%, 50%, and 0% were applied to the soil before planting the lettuce and, ANOVA analysis and Duncan test (at α=5%) were conducted. The results showed that a joint application of inorganic and organic fertilizers affects significantly the yield and yield parameters of the lettuce whilst the separate application of organic fertilizer affects significantly the lettuce content in N, P, K, Ca and Mg. Compared to GM, the application of GM-derived BC increases significantly the lettuce content in Zn and decreases its content in Cu. In addition, the highest total yield of lettuce was obtained with a joint combination of GM, BC, and 100% NPK (100 kg N ha-1, 100 kg P2O5 ha-1 and 100 kg K2O ha-1). Consequently, this combination of organic and inorganic fertilizers is favorable fertilization in producing lettuce.

Plant nutrient contents and spatial distribution patterns of toxic element concentrations in mine site soils

Open-pit coal mining causes land and soil degradation and negatively affects soil properties. It is of great importance to determine variabilities in soil properties of the abandoned area after the mine is closed and to bring it back to nature by implementing appropriate rehabilitation programs. The aim of this study was to evaluate plant nutrient availability and toxic element pollution in an abandoned coal mine site. The results indicated that the amounts of plant-available P and K are quite low (<90 kg P2O5 ha-1) and low to moderate (<170 kg K2O ha-1), respectively. The concentrations of plant available Fe (>4.5 mg kg-1) and Cu (>0.2 mg kg-1) are too high in the whole study site. Soils in the study area generally have low organic matter content with ranging from 0.42% to 3.67%. Toxic element concentrations, especially Ni (>75 mg kg-1) and Cr (>100 mg kg-1), are extremely above the optimum levels, posing a great risk in the open-pit area (abandoned), the dump sites and the coal storage area.

Effects of Different Soil Tillage Methods, Phosphorus Fertilizer Doses and Bacteria Inoculation on Yield and Yield Components in Chickpea (Cicer arietinum L.)

This study was conducted to determine the effect of different soil tillage methods, phosphorus levels and bacteries on the yield and yield components in chickpea under Muğla/Turkey conditions in 2017 and 2018. Chickpea variety Inci was used as materials in this study. The study was conducted at split-split plot design with the three replication. Soil tillage methods was in main plots, phosphorus doses in subplots and bacteria application in sub-sub plots. According to finding of this study, reduced tillage system for chickpea production was the most efficient tool for obtaining the high yield performance. It is seen that phosphorus fertilizer applications cause an increase in yield in chickpea. In general, the application of rhizobia and phosphate solubilizing bacteria separately supported the yield increase in the plant. As a result, only rhizobia application, 60 kg ha-1 P2O5 and reduced tillage gave the highest yield.

Effect of Phosphorus, Sulphur and Gibberellic Acid on Growth, Root Nodules and Yield of Soybean [Glycine max (L.) Merrill

An experiment was conducted during kharif season 2020 at Instructional Farm, College of Agriculture, Ummedganj, Kota. The experiment comprised twenty-four treatment combinations, having four levels of phosphorus viz., 0, 20, 40 and 60 kg ha-1, three levels of sulphur viz., 15, 30 and 45 kg ha-1 and foliar spray of gibberellic acid viz., no spray and spray of GA3 @ 75 ppm laid out in sub-sub split-plot design with three replications. Results showed that application of 60 kg P2O5 ha-1 had significant effect on plant height, dry matter accumulation plant-1, branches plant-1 at 30, 60 DAS and at harvest, root nodules plant-1 and their dry weight at 45 DAS while root nodules plant-1 and their dry weight at 45 DAS andseed yield (1956 kg ha-1) over application of 40, 20 kg P2O5 ha-1 and control. Significantly higher seed yield (1956 kg ha-1) was recorded under application of 60 kg P2O5 ha-1 over application of 20 kg P2O5 ha-1 and control. However, it was found at par with application of 40 kg P2O5 ha-1. Application of 45 kg sulphur ha-1 had significantly higher plant height (cm) at 60 DAS and at harvest, dry matter accumulation (g plant-1) at 30, 60 and at harvest stages, branches plant-1 at 30, 60 and at harvest stage, number of root nodules and their dry weight (g) and seed yield (1742 kg ha-1) which was found at par with application of 30 kg sulphur ha-1 over 15 kg sulphur ha-1. Application of gibberellic acid @ 75 ppm as foliar spray gave significantly higher plant height (cm) at 60 DAS and at harvest stage, dry matter accumulation (g plant-1) at 60 DAS and at harvest, branches plant-1 at 30, 60 DAS and harvestand seed yield (1770 kg/ha) over control.

Inductive Cum Target Yield Model Based Fertilizer Prescription for Chickpea Cultivation in North Western Mollisol

A field experiment was conducted in an Aquic hapludoll at D7 block of Norman E. Borlaug Crop Research Centre, G.B. Pant University of Agriculture and Technology, Pantnagar (29° N Latitude and 79°29’ E Longitude), as the per technical program of All India Coordinated Research Project on Soil Test Crop Response Correlation to study the effect of soil and applied nutrients on chickpea to ensure balanced fertilization. Response to selected combinations of three levels of FYM (0, 5 and 10 t ha-1), four levels of nitrogen (0, 10, 20 and 30 kg ha-1 ), four levels of phosphorus (0, 20, 40 and 60 kg P2O5 ha-1) and four levels of potassium (0, 10, 20 and 30 kg K2O ha-1) at different fertility levels of chickpea was studied. Basic data for fertilizer prescription was computed on the basis of soil analysis, nutrient uptake and grain yield. Nutrient requirement for production of one quintal of grain yield of chickpea was found to be 4.41 kg nitrogen, 0.62 kg phosphorus and 2.53 kg potassium. Percent contribution of nitrogen, phosphorus and potassium was 37.05, 72.16 and 35.61, from soil, whereas from other sources as FYM was 68.31, 16.15 and 37.20 percent; chemical fertilizer 160.01, 16.79 and 93.51 and conjoint joint use of chemical fertilizer with FYM 64, 15.57 and 95.22 in terms of N, P and K respectively. Fertilizer prescription equations were generated by these basic data. These fertilizer prescription equations are valuable for efficient and judicious use of costly fertilizers to improve farmer’s economic conditions.

Effect of FYM, Phosphorus and PSB on Growth, Yield Attributes, Quality, Nutrient Content (%) and Uptake by Kharif Green Gram [Vigna radiata (L.) Wilczek

This experiment was carried out for two consecutive years (2020 and 2021) during Kharif season at Student’s Instructional Farm (SIF) of Department of Agronomy, Chandra Shekhar Azad University of Agriculture &amp; Technology, Kanpur, Uttar Pradesh, India to assess the effect of Farm Yard Manure (FYM), phosphorus levels and Phosphate solubilizing bacteria (PSB) on growth and yield of Green gram with variety Shweta (K.M. 2241) was laid out in Factorial Randomized Block Design (FRBD) and replicated thrice. This experiment included 20 treatment combinations, the levels of FYM viz., control (F0), 1.0 t (F1), 2.0 t (F2) and 3.0 t (F3) and levels of phosphorus viz., PSB only (P1), 20 kg P2O5 (P2), 20 kg P2O5 + PSB (P3), 40 kg P2O5 (P4) and 40 kg P2O5 + PSB (P5). The result of this study showed the interaction effect of FYM, phosphorous &amp; PSB were non-significant. In the different levels of FYM, the 3.0 tons ha-1 FYM resulted in significantly higher growth attributes viz., plant height (40.60cm) at maturity, No. of branches plant-1 (4.95) at maturity, number of nodules plant-1 (24.85) at 60 DAS and dry weight of nodules plant-1 (14.34g) at 60 DAS, yield attributes viz., number of pods plant-1 (14.70), weight of pod plant-1 (7.44g), pod length (6.55cm) , and test weight (41.36g), yield viz. grain or seed yield (894kg ha-1) and quality parameters viz., protein content (23.90%), protein yield (214kg ha-1), nutrient contents i.e. nutrients uptake by grain and straw of Green gram compared to other treatments and control. Among the different levels of phosphorous &amp; PSB, 40 kg P2O5 ha-1 + PSB resulted the highest values of growth attributes viz., plant height (38.54cm) at maturity, No. of branches plant-1 (4.52) at maturity, number of nodules plant-1 (23.19) at 60 DAS and dry weight of nodules plant-1 (13.42g) at 60 DAS, yield attributes viz., number of pods plant-1 (13.99), weight of pod plant-1 (6.57g), pod length (6.35cm), and test weight (40.85g), yield viz. grain or seed yield (825 kg ha-1), and quality parameters viz., protein content (23.84%), protein yield (197kg ha-1), nutrient contents i.e. nutrients uptake by grain and straw. Thus, it is possible to maximize the growth attributes, yield attributes, yield and quality of Green gram with application 3.0 tons ha-1 FYM and 40 kg P2O5 ha-1 + PSB.

ONION RESPONSE TO PHOSPHORUS FERTILIZER

Onion (Allium cepa L.) is among the most important food plants with high nutritional value, but insufficient application of phosphorous is one of the constraints to the yields. Research on onion responses to different doses of phosphorus will optimize fertilizer dose, making the practice more competitive with less environmental effects. Three field experiments were carried out fortwo years to evaluate the effect of different phosphorus levels on the yield of onion in Randomized Complete Block Design (RCBD) with three replications and four treatments (80, 120, 160, and 200 Kg P2O5 ha-1 ) along with N and K at a rate of 60 Kg ha-1 . From the results, it can be concluded that the onion responded to applied phosphorus doses and the variance analysis showed that the P effect was significant. The maximum (18.58 t ha-1 ) onion bulb yield was obtained from a combination of NPK @60-200-60 Kg ha-1 and was appeared statistically equal to the yield (18.41 t ha-1 ) obtained from NPK @ 60-160-60 Kg ha-1 which also found suitable, effective and economically viable for the cultivation of onions in Punjab, Pakistan.

Effect of planting distance on the production of full of and long grains with addition of NPK and organic acids characters and dates on yield sunflower (Helianthus annuus L.)

A field experiment was conducted during the spring season 2021 in agriculture field in Al-Rumaitha district, which was 25 km from the center of Al-Muthanna Governorate, to study the effect of plant distance and different fertilizer combinations on the purchasing value and the size of sunflower grains (Shumoos). A factorial experiment was carried out by using the split plot Experiment, according to a randomized complete block design R.C.B.D with three replicates. The experiment included the two factors , the first factor was four plant distance : (55, 45, 35 and 25) cm, and the second was four different fertilizer combinations of N.P.K and organic acids: (100%, 1/4, 1/2 and 3/4) kg ha-1 . The grains were sown on 03-15-2021 with different distances between plant and 75 cm between one line and another. The plant wide spacing between sunflower plants significantly affected most of the yield traits; the distance of 55 cm was superior in the highest mean disc diameter, number of filled grains, weight of 1000 gm and harvest index, while the sowing distance distance of 25 cm was significantly superior in giving the highest mean of total grain yield. The addition of different fertilizer combinations affected all vegetative growth characteristics, fertilizer level exceeded F2 (120 kg N ha-1 ,75 kg P2O5 ha-1 ,120 kg K2O ha-1 +30 kg ha-1 humic and fulvic) on disc diameter, number of filled grains, weight of 1000 grains, harvest index and total grain yield. The effect of the interaction between the two factors of the study was significant on most of the studied traits. the treatment F2D4 significantlysuperiority, by giving it the highest average for each of the disc diameter, the number of filled grains, weight of 1000 grains, and the harvest index, whereas, the combination F2D1 gave the highest Mean for the total grain yield

Effect of Rock Phosphate, Single Super Phosphate and Phosphorus Solubilizing Bacteria on Phosphorus Concentration and Dry Matter Yield of Paddy

The majority of tropical and subtropical soils are acidic which are mostly deficient in phosphorus and have strong phosphorus sorption capacity. Exploring different phosphorus inputs is essential not only to increase crop production but also to improve soil phosphorus status to avoid further soil degradation. Acidic nature of the soils of these regions help to solubilize the rock phosphate and increases the amount of phosphorus that is made available to the plants. A pot experiment was conducted in Department of Soil Science and Agricultural Chemistry of College of Agriculture, Central Agricultural University, Imphal (Manipur) during kharif season of 2021 to study the effect of rock phosphate, single super phosphate and phosphorus solubilizing bacteria on phosphorus concentration and dry matter yield of paddy. To each experimental pot, recommended dose of 60 kg of N ha-1 in the form of urea and 30 kg K2O ha-1 in the form of muriate of potash were applied as basal and thoroughly mixed with the soil. Rock phosphate and single super phosphate were administered to the pots as phosphorus sources according to different sets of treatment based on the recommended amount of 40 kg P2O5 ha-1 for paddy. Seeds were treated with Bacillus megatherium. Result revealed that the changes in soil phosphorus concentration and dry matter yield of paddy were significantly affected by rock phosphate applied either singly or in combination with single super phosphate and phosphorus solubilizing bacteria. All the parameters showed different trend of changes during the whole crop growth stages till harvest. Among the treatments higher values were recorded in soil treated with T10 (50% recommended dose of P2O5 from single super phosphate + 50% recommended dose of P2O5 from rock phosphate + phosphorus solubilizing bacteria). Addition of phosphorus solubilizing bacteria enhances release of less soluble and fixed forms into easily available form as well as reduces phosphorus fixation. Efficiency of rock phosphate as phosphorus source for crop production is improved by the solubility effect of phosphorus solubilizing bacteria.

Optimizing phosphate fertilizer input to reduce phosphorus loss in rice-oilseed rape rotation.

Identifying the major sources and critical periods of P loss from agricultural fields provides important guidance for reducing P loss. A rice-oilseed rape rotation with no P fertilization (NP, control), medium P fertilization (MP, 90kg P2O5 ha-1 season-1), and high P fertilization (HP, 180kg P2O5 ha-1 season-1) was conducted from 2019 to 2021 in the middle Yangtze River Basin. Runoff and leaching P losses were measured simultaneously using runoff event monitoring and a percolation device. Applying P fertilizer increased the P concentration in the field ponding water and percolation water of the rice-oilseed rape rotation. During the rice growing season, total P (TP), dissolved P (DP), and particulate P (PP) concentrations in the field ponding water and percolation water peaked 1day after P was applied, and then decreased rapidly. After 10days of fertilization, P concentration in the field ponding water of the MP treatment decreased to a minimum and stabilized, while the HP treatment extended this period to 20days. The highest P concentration in percolation water was observed at the first sampling during the oilseed rape season, and then it continued to decrease. Inputting P fertilizer increased P loss by 55.0-109.9% compared to the NP treatment, with annual P losses of 0.89-1.10kg P ha-1, of which runoff loss accounted for 61.7-62.9%. Fertilization and precipitation resulted in varied P loss within and between seasons. Runoff from heavy precipitation during the rice season was the main source of P loss, while PP accounted for 54.7-77.6% of runoff P loss. The strong utilization of soil P by rice resulted in a lower demand for exogenous P fertilizer than oilseed rape. Excessive P input increased the soil P surplus and vertical migration. Therefore, reducing rice season P fertilizer inputs to achieve annual P balance in rice-oilseed rape rotation can effectively reduce soil P surplus and loss while ensuring crop P demand, and the initial 10 d after fertilization in the rice season was a critical period for reducing P runoff loss.

Effect of Different Rates and Time of Application of Phosphorus on Yield, Soil Fertility, Nutrient Uptake and Monetary Returns of No-till Maize (Zea mays L.) after Lowland Rice

Field experiment was conducted during dry seasons for 2 consecutive years at College of Agriculture, Rajendranagar, Hyderabad on no-till maize after lowland kharif rice on sandy clay loam soil. The experiment was laid out in randomized block design with factorial concept and replicated thrice. Treatments executed are three Phosphorus levels (30, 45 and 60 kg P2O5 ha-1) and three Phosphorus application times (at 10 days before harvest of rice, at the time of sowing of maize and at the time of first irrigation to maize). The results revealed that application of 60 kg P2O5 ha-1 recorded superior grain and stover yield, gross returns, net returns, benefit cost ratio and nutrient uptake (Nitrogen, Phosphorus and Potassium) at crop harvest over that of 45 and 30 kg P2O5 ha-1. But, application of 60 kg P2O5 ha-1 left behind the soil with lower amount of available Nitrogen and Potassium and higher Phosphorus status after harvest of the crop. Application of phosphorus at 10 days before harvest of rice and at the time of sowing of maize being on par resulted in better grain and stover yield of maize, gross returns, net returns, benefit cost ratio and nutrient uptake (Nitrogen, Phosphorus and Potassium) at crop harvest over its delayed application (at the time of first irrigation to maize). The application of Phosphorus at 10 days before harvest of rice or at the time of sowing of maize depleted greater amount of available Phosphorus from the soil than its application along with first irrigation.

Effect of Phosphorous and Potassium on Growth Parameters, Yield and Yield Attributes of Chickpea (Cicer arietinum L.) under the Rainfed Condition in Chitrakoot, India

The present study investigate the effect of phosphorous and potassium on growth parameters, yield and yield attributes of chickpea (Cicer arietinum L.) under the rainfed condition in Chitrakoot, India. Field experiments were carried out to investigate the effect of phosphorus and potassium on chickpea growth parameters, yield components, and yield during the rabi season of 2021-22 at Rajoula Agriculture farm, Mahatma Gandhi Chitrakoot Gramodaya Vishwavidyalaya Chitrakoot, Satna (M.P.). The experiment consist of nine treatments combinations in factorial randomized block design with three replications consisted of three levels of phosphorous (50, 60 and 70 kg ha-1) and three potassium levels (30, 40 and 50 kg ha-1). Chickpea variety IPC-2011-112 was grown with the recommended agronomic practices. On the basis of results emanated from investigation it can be concluded that among the growth parameters maximum plant height at 90 DAS is 37.40 cm, maximum number of branches at 90 DAS is 32.53 and maximum number of nodules plant-1 at 45 DAS is 46.00 during the study were associated with the treatment T9 [70 kg P2O5 ha-1+ 50 kg K2O ha-1]. Similarly, among the yield components and productivity parameters maximum values in relation to number of pod plant-1 (69.33), number of seed pod-1 (1.73), 100 grain wt. (22.66 gm) and grain yield (16.85 q ha-1) was also found in the treatment T9 [70 kg P2O5 ha-1+ 50 kg K2O ha-1].