Moss carpets constrain the fertilizing effects of herbivores on graminoid plants in arctic polygon fens

Botany ◽  
2009 ◽  
Vol 87 (12) ◽  
pp. 1209-1222 ◽  
Author(s):  
Rémy Pouliot ◽  
Line Rochefort ◽  
Gilles Gauthier

We conducted a fertilization experiment in polygon fens that were grazed by Greater Snow Geese on Bylot Island (Canadian Arctic) to determine whether mosses can interfere with nutrient cycling and thereby prevent a direct fertilizing effect of herbivore faeces on vascular plants. We measured the effects of nitrogen (N), phosphorus (P), and faecal addition on growth parameters and nutrient content of graminoids and mosses over a 2 year period. Growth and nutrient content of graminoids were enhanced only for high levels of N addition (5 g·m–2 per season), and showed little response to P addition. Although the growth of mosses showed a slight response to N or P addition, it is primarily nutrient content that was generally enhanced at all levels of fertilization. In many cases, stronger responses were detected when N and P were applied in combination, rather than singly. Addition of goose droppings had no effect on any measured parameters. Our results suggest that bryophytes act as a natural barrier by absorbing nutrients from external additions, thus blocking the access of highly assimilable nutrients to graminoid plant roots. At increased levels of N addition, bryophytes were apparently saturated so the nutrient surplus leached down to roots and was thus available for graminoid plant growth. The presence of a thick moss layer likely explains why the deposition of faeces by herbivores such as geese has no effect on graminoid growth in arctic polygon fens.

Agriculture ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 553
Author(s):  
Inga-Mareike Bach ◽  
Lisa Essich ◽  
Torsten Müller

Despite phosphorus resources on Earth being limited, over fertilization in many agricultural situations causes significant resource consumption. Phosphorus-recycling within agricultural production can reduce global dilution into the environment and is thus essential to secure sustainable future supply. This study investigated the fertilization efficacy of phosphorus fertilizers recycled from biogas digestates in maize shoots grown under controlled greenhouse conditions, in two soils, in a pot experiment. Variables investigated were plant-available phosphorus in soil, plant biomass production, and concentration of phosphorus, calcium, and magnesium in shoots. Soils were treated with three different fertilizer fractions, separated from biogas digestates, at equivalent phosphorus concentrations, using different combinations and application techniques, isolated or in combination, and compared to triple superphosphate (TSP) as a reference. One of the fractions (P-Salt) had effects on biomass production and plant phosphorus concentration equivalent to TSP in agricultural surface soil. In the second soil (with less active soil life and nutrient content), equivalence to TSP was achieved with combinations of two recycled fractions (P-Salt and dried solids). The enhancement of the phosphorus fertilizing effect by the solids was synergistic, indicating that the solids had a soil conditioning effect. The results show that biogas digestates are a valuable source for phosphorus recycling of fractions that have equivalent or even superior fertilizing properties compared to TSP.


2016 ◽  
Vol 13 (11) ◽  
pp. 3503-3517 ◽  
Author(s):  
Mianhai Zheng ◽  
Tao Zhang ◽  
Lei Liu ◽  
Weixing Zhu ◽  
Wei Zhang ◽  
...  

Abstract. Nitrogen (N) deposition is generally considered to increase soil nitrous oxide (N2O) emission in N-rich forests. In many tropical forests, however, elevated N deposition has caused soil N enrichment and further phosphorus (P) deficiency, and the interaction of N and P to control soil N2O emission remains poorly understood, particularly in forests with different soil N status. In this study, we examined the effects of N and P additions on soil N2O emission in an N-rich old-growth forest and two N-limited younger forests (a mixed and a pine forest) in southern China to test the following hypotheses: (1) soil N2O emission is the highest in old-growth forest due to the N-rich soil; (2) N addition increases N2O emission more in the old-growth forest than in the two younger forests; (3) P addition decreases N2O emission more in the old-growth forest than in the two younger forests; and (4) P addition alleviates the stimulation of N2O emission by N addition. The following four treatments were established in each forest: Control, N addition (150 kg N ha−1 yr−1), P addition (150 kg P ha−1 yr−1), and NP addition (150 kg N ha−1 yr−1 plus 150 kg P ha−1 yr−1). From February 2007 to October 2009, monthly quantification of soil N2O emission was performed using static chamber and gas chromatography techniques. Mean N2O emission was shown to be significantly higher in the old-growth forest (13.9 ± 0.7 µg N2O-N m−2 h−1) than in the mixed (9.9 ± 0.4 µg N2O-N m−2 h−1) or pine (10.8 ± 0.5 µg N2O-N m−2 h−1) forests, with no significant difference between the latter two. N addition significantly increased N2O emission in the old-growth forest but not in the two younger forests. However, both P and NP addition had no significant effect on N2O emission in all three forests, suggesting that P addition alleviated the stimulation of N2O emission by N addition in the old-growth forest. Although P fertilization may alleviate the stimulated effects of atmospheric N deposition on N2O emission in N-rich forests, this effect may only occur under high N deposition and/or long-term P addition, and we suggest future investigations to definitively assess this management strategy and the importance of P in regulating N cycles from regional to global scales.


2021 ◽  
Vol 50 (9) ◽  
pp. 2615-2624
Author(s):  
Muzaffer İpek ◽  
Şeyma Arıkan ◽  
Ahmet Eşitken ◽  
Lütfi Pırlak ◽  
Mesude Figen Dönmez ◽  
...  

The highly calcareous soil limits plant growth parameters due to inadequate uptake of plant nutrients. Calcareous soil conditions affect plant growth through impaired chlorophyll synthesis, root growth, enzyme synthesis, and nutrient uptake. To overcome the negative effect of calcareous soil, six bacterial strains namely Alcaligenes 637Ca, Agrobacterium A18, Staphylococcus MFDCa1, Staphylococcus MFDCa2, Bacillus M3, and Pantoea FF1 were inoculated in one-year-old plants of peach cultivar ‘Elegant Lady’ grafted onto GF677 and Nemaguard rootstocks. The bacterial treatments were observed to improve plant growth and nutrient content compared to the control. Moreover, the GF677 rootstock was observed to be more tolerant to high calcareous soil conditions than Nemaguard, showing better plant growth and nutrient content. At the Nemaguard rootstocks, the largest leaf area was observed to be upon inoculation with MFDCa2 (29.1 cm2), FF1 (28.8 cm2), and M3 (28.1 cm2), whereas at the GF677 rootstock, the highest leaf area was observed upon inoculation with MFDCa1 (34.7 cm2), FF1 (32.6 cm2), and 637Ca (31.5 cm2). The leaf iron content was higher in bacterial treatments than the control. In the Nemaguard rootstock, the highest iron content was measured in plants inoculated with 637Ca (133.49 mg kg–1) and M3 (127.64 mg kg–1), whereas in the GF677 rootstock, the treatments MFDCa1 (131.51 mg kg–1), 637Ca (131.21 mg kg–1), FF1 (127.72 mg kg–1), and M3 (127.68 mg kg–1) resulted in high iron content. The results indicate that bacterial inoculations have a significant potential to improve plant growth and can be used as biofertilizers for peach grafted onto Nemaguard and GF677 in high calcareous soil conditions.


2020 ◽  
Vol 8 (11) ◽  
pp. 1828 ◽  
Author(s):  
Zongwei Xia ◽  
Jingyi Yang ◽  
Changpeng Sang ◽  
Xu Wang ◽  
Lifei Sun ◽  
...  

Increased soil nitrogen (N) from atmospheric N deposition could change microbial communities and functions. However, the underlying mechanisms and whether soil phosphorus (P) status are responsible for these changes still have not been well explained. Here, we investigated the effects of N and P additions on soil bacterial and fungal communities and predicted their functional compositions in a temperate forest. We found that N addition significantly decreased soil bacterial diversity in the organic (O) horizon, but tended to increase bacterial diversity in the mineral (A) horizon soil. P addition alone did not significantly change soil bacterial diversity but mitigated the negative effect of N addition on bacterial diversity in the O horizon. Neither N addition nor P addition significantly influenced soil fungal diversity. Changes in soil microbial community composition under N and P additions were mainly due to the shifts in soil pH and NO3− contents. N addition can affect bacterial functional potentials, such as ureolysis, N fixation, respiration, decomposition of organic matter processes, and fungal guilds, such as pathogen, saprotroph, and mycorrhizal fungi, by which more C probably was lost in O horizon soil under increased N deposition. However, P addition can alleviate or switch the effects of increased N deposition on the microbial functional potentials in O horizon soil and may even be a benefit for more C sequestration in A horizon soil. Our results highlight the different responses of microorganisms to N and P additions between O and A horizons and provides an important insight for predicting the changes in forest C storage status under increasing N deposition in the future.


Agronomy ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 711
Author(s):  
Mohamed M. El-Mogy ◽  
Mohamed Abdel M. Wahab ◽  
Mohamed B. I. El-Sawy ◽  
Aditya Parmar

Foliar application of micronutrients has become a common farm management practice to increase the overall yield of various crops. However, the effects of foliar fertilization on shelf life and postharvest quality of the crops are rather under-researched. The aim of this field experiment was to evaluate the effect of foliar application of individual mineral nutrients (calcium (Ca), zinc (Zn), manganese (Mn), and iron (Fe) on pre and postharvest quality of broccoli. The broccoli plants were subjected to single foliar sprays of either Ca, Fe, Zn, or Mn, which was repeated four times during plant growth at a 1 g/kg concentration. Once harvested, the broccoli heads were refrigerated at 4 °C for 28 days. Our results indicated that foliar application of Ca, Zn, Mn, and Fe did not have a significant effect on plant growth parameters, apart from enhancing Soil Plant Analysis Development (SPAD) chlorophyll meter values. However, during postharvest, foliar application treatment showed a positive response on weight loss during storage and reduction in yellowing of the broccoli heads. Foliar treatments increased the concentration of Nitrogen (N), Phosphorus (P), Ca, Zn, Mn and Fe significantly in the broccoli head tissue. Total chlorophyll content, total phenolic compound, ascorbic acid, peroxidase activity, glucoraphanin and glucobrassicin and flavonoids were significantly increased by all foliar treatments. Crude protein content and sulforaphane were enhanced by Ca and Mn treatments. Overall, foliar application of the investigated mineral nutrients may prove beneficial in improving the shelf-life and nutrient content of broccoli during postharvest handling and storage.


2020 ◽  
Author(s):  
Yawen Shen ◽  
Tianle Xu ◽  
Biao Zhu

<p>Living roots and arbuscular mycorrhiza fungi (AMF) are widespread in most terrestrial ecosystems and play an important role in ecosystem nitrogen (N) cycling. However, the influence of living roots and AMF on soil N<sub>2</sub>O emissions remains poorly understood. In this study, we conducted a pot experiment with ryegrass (Lolium perenne) growing in a greenhouse for three months with three factors: root and AMF presence (None or unplanted, Root or with roots, and Root+AMF or with roots colonized by AMF), two N addition levels (N0 and N1 with 0 and 50 mg N kg<sup>-1</sup> soil) and two P addition levels (P0 and P1, with 0 and 20 mg P kg<sup>-1</sup> soil).</p><p> </p><p>Our results showed that N addition didn’t have significant effect on N<sub>2</sub>O emission, however, we detected significant effects of Root and Root+AMF, particularly under P addition. Though the colonization of AMF didn’t significantly influence N<sub>2</sub>O emission, the presence of roots (Root and AMF+Root treatments) deceased N<sub>2</sub>O emission by 58%-67% compared with the None treatment. P addition increased (+134%) N<sub>2</sub>O emission from unplanted soil but decreased (74%-98%) N<sub>2</sub>O emission under planted soil regardless of AMF colonization. Moreover, there were no significant relationship between N<sub>2</sub>O emission and soil pH, NH<sub>4</sub><sup>+</sup>-N and net N mineralization. The lower N<sub>2</sub>O emission from rooted treatments were mainly due to the lower soil NO<sub>3</sub><sup>-</sup>-N (and MBN) content which might be immobilized by plant biomass, while the higher N<sub>2</sub>O emission from unplanted soil under P addition was attributed to increased soil available (r=0.760, P<0.01) and total (r=0.654, P<0.01) phosphorus content. We conclude that root presence and P addition played an important role in regulating N<sub>2</sub>O emission from P-limited soils.</p><p></p>


2016 ◽  
Vol 28 (1) ◽  
pp. 43-50
Author(s):  
Farzana Yasmin ◽  
Sayma Khanom ◽  
Shahid Akhtar Hossain

A field experiment was conducted in Khulna district to evaluate the growth and nutrient composition on stem Amaranth by irrigating with different water sources. Water that has been used as treatment are saline water, T1 and treated water, T2 (water from a project called Managed Aquifer Recharge (MAR)). A field condition was also included, T0 (control). All the growth parameters of the crop were significantly improved for treated water. Whereas, N, P, and K uptake (3.54, 39.56 and 564.42 kg/ha, respectively) were increased and S was decreased (48.76 kg/ha) for treated water (T2) compared to control (T0). Carbohydrate and total dietary fiber (TDF) is increased (6.09 and 6.87 g/100g) while protein, fat, ash and energy in the leaf of stem Amaranth is decreased (3.16, 0.46, 3.26 g/100g and 54.94 Kcal/100g respectively) by irrigating with T2 water. Moreover, carbohydrate content is increased (3.55 g/100 g) in treated water (T2) but protein, fat, ash, TDF and energy in the stem of stem Amaranth is decreased. EC, pH, Na, K, Ca and Mg of the soil were decreased markedly by applying treated water (T2) and other nutrients present in soil also varies. From the study, it can be concluded that the best alternate source of water for irrigation is MAR water (T2) which can improve plant nutrient content and uptake and soil nutrient status.Bangladesh J. Sci. Res. 28(1): 43-50, June-2015


2020 ◽  
Vol 29 (2) ◽  
pp. 201-208
Author(s):  
TT Purna ◽  
AHMZ Ali ◽  
Md Khalilur Rahman

A pot experiment was conducted to evaluate the effects of zinc and vermicompost on the growth, yield and nutrient content of soybean (Glycine max L.) plant. The treatment variables were control (‒Zn and ‒VC), VC 5 ton/ha, Zn 1 kg/ha, Zn 2 kg/ha, Zn 3 kg/ha, Zn 1 kg/ha + VC 5 ton/ha, Zn 2 kg/ha + VC 5 ton/ha and Zn 3 kg/ha + VC 5 ton/ha. Application of zinc and vermicompost showed a significant effect on the growth parameters and macro- and micronutrients uptake by the plant. The highest average plant height (164 cm), leaf number (80 nos./plant), leaf area (3360 cm2/plant), fresh weight (49.03 gm/plant), dry weight (24.54 gm/plant), fruit length (9.4 cm), fruit number per plant (5 nos. /plant) were recorded for Zn 1 kg/ha + VC 5 ton/ha treatment while the lowest values were observed in control at harvest. Results of the growth parameters varied significantly (p ≤ 0.05) with time. It was observed that, the overall best growth performance was achieved in Zn 1 kg/ha + VC 5 ton/ha. Dhaka Univ. J. Biol. Sci. 29(2): 201-208, 2020 (July)


2018 ◽  
Vol 4 (4) ◽  
pp. 247-251 ◽  
Author(s):  
J.N. Kinyuru ◽  
C. Kipkoech

The need for mass-production of crickets is increasing with continued awareness. Cricket farming has been introduced with considerable success among small-holder farmers in the warmer, low altitude Lake Victoria regions of Kenya. Efforts are however on-going to introduce the farming in cooler, higher altitude areas in the interest of expanding the enterprise and increase mass production. A pilot farm was established at a farm located 1,519 meters above sea level with a temperature range of 17-22 °C. Initial egg stock was incubated at the farm under room conditions in the month of November to December. Different agricultural side streams and farm weeds were tested as probable cricket feed. Hatch rate, duration of hatching, preferred food types, mortality, weight gain and nutrient content at different ages were assessed. The hatch rate averaged 60%, mortality for hatchlings (pinheads) was below 2% while a steady weight gain was observed over a 12 weeks growth period with highest maximum weight being 2.03 grams per cricket. All agricultural side streams were accepted by the crickets and the wandering Jew weed was among the preferred feed and a source of significant nutrient for the crickets. Protein content ranged from 36-60% while fat content was 12-25%. Cricket production can therefore be promoted in the higher altitude, cooler areas in order to promote industrial exploitation of the crickets in combating food and nutrition insecurity.


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