Growth Enhancement, Uptake of N, P, K Nutrients and Production of Maize in an Entisol of Kalidawir, Tulungagung due to Application of Cow Manure Fertilizer and NPK Fertilizer

Entisols are newly formed soil types and are commonly found in Indonesia, with a distribution of ±3 million ha distribution. Entisol Kalidawir has a slightly acidic pH value of 5.8 and contains very low total-nitrogen (N) and available-phosphorus (P) nutrients, calcium (Ca), sodium (Na) and magnesium (Mg) in the exchangeable base are also low and clay loam texture. Low soil nutrients and organic matter can have an impact on plant growth and production Maize is one of the most widely cultivated food crops in Indonesia. The purpose of this study was to analyze various doses of the combination of cow manure and NPK fertilizer on N, P and potassium (K) uptake, growth and production of maize. The results showed that the application of 20 t ha-1 of cow manure and 400 kg ha-1 of NPK fertilizer at observations 27 and 54 days after planting increased growth in height and number of leaves of corn plants and increased nutrient uptake of N, P, and K, respectively. Also reached 1, 0.14, and 0.82 g plant-1 and 5.52, 0.83, and 5.11 g plant-1. In addition, it produces the highest corn production of 10.53 t ha-1.

STOP1 Regulates LKS1 Transcription and Coordinates K+/NH4+ Balance in Arabidopsis Response to Low-K+ Stress

Potassium and nitrogen are essential mineral elements for plant growth and development. The protein kinase LKS1/CIPK23 is involved in both K+ and NH4+ uptake in Arabidopsis root. The transcripts of LKS1 can be induced by low K+ (0.1 mM) and high NH4+ (30 mM); however, the molecular mechanism is still unknown. In this study, we isolated the transcription factor STOP1 that positively regulates LKS1 transcription in Arabidopsis responses to both low-K+ and high-NH4+ stresses. STOP1 proteins can directly bind to the LKS1 promoter, promoting its transcription. The stop1 mutants displayed a leaf chlorosis phenotype similar to lks1 mutant when grown on low-K+ and high-NH4+ medium. On the other hand, STOP1 overexpressing plants exhibited a similar tolerant phenotype to LKS1 overexpressing plants. The transcript level of STOP1 was only upregulated by low K+ rather than high NH4+; however, the accumulation of STOP1 protein in the nucleus was required for the upregulation of LKS1 transcripts in both low-K+ and high-NH4+ responses. Our data demonstrate that STOP1 positively regulates LKS1 transcription under low-K+ and high-NH4+ conditions; therefore, LKS1 promotes K+ uptake and inhibits NH4+ uptake. The STOP1/LKS1 pathway plays crucial roles in K+ and NH4+ homeostasis, which coordinates potassium and nitrogen balance in plants in response to external fluctuating nutrient levels.

Potassium Bioavailability in a Tropical Kaolinitic Soil

Some plant species are able to acquire non-exchangeable forms of K, which improve K availability and cycling in cropping systems, and which may explain the lack of response to K. However, this would not be expected in soils dominated by kaolinite. The aim of this study was to assess non-exchangeable K (Kne) use by three selected plant species grown in a tropical Haplic Plinthosol with low exchangeable K (Ke). A greenhouse experiment was conducted with soybean (Glycine max L., Merr.), maize (Zea mays L.), and ruzigrass (Urochloa ruziziensis) with or without K fertilization for three growing cycles. The crop treatments were compared with a control without plants. In the absence of K fertilization, all the tested plants were able to use non-exchangeable K and non-exchangeable K contributed more than 80% of the K demand of the plants in the first growing cycle, even in this kaolinitic soil. In the first growing cycle, soybean and maize took up more non-exchangeable K than ruzigrass, concomitant with higher dry matter yields. Over the three crop cycles, as both biomass yield and K uptake decreased in the unfertilized systems, the dependence of plants on non-exchangeable K decreased. Unfertilized ruzigrass showed a strong ability to acquire non-exchangeable K from the soil. Over the course of three growing cycles, K application decreased the absolute uptake of non-exchangeable K as well as its fractional contribution to total K uptake by the crops.

Transcriptional networks underpinning ploidy related increased leaf potassium in neo-tetraploids

Neo-tetraploid Arabidopsis thaliana have elevated leaf potassium (K) driven by processes within the root. The root transcriptome of neo-tetraploids is distinct from diploids, with evidence of altered K homeostasis. Mutational analysis revealed that the canonical K-uptake transporters AKT1 and HAK5 are not required for this elevated leaf K in neo-tetraploids, while the endodermis, root hairs, and SOS signaling are. Contrasting the root transcriptomes of neo-tetraploids and diploids of mutants that block the neo-tetraploid K phenotype, allowed us to identify 91 differentially expressed genes associated with elevated leaf K in neo-tetraploids. This set of genes connects WGD to elevated leaf K, and is enriched in functions such as cell wall and Casparian strip development, and ion-transport, in the endodermis, root hairs, and procambium. This gene set provides tools to test the intriguing idea of recreating the physiological effects of WGD within a diploid genome.

Evaluating The Performance of Nutrients Uptake Capabilities and Enzymatic Activities in The Different Green Manures

Winter green manure potentially uptake large amount of phosphorus (P) and potassium (K) from the soil. However, the mechanism underlying nutrient uptake in green manure varieties remain elusive. This study illustrates the P and K uptake potential in different leguminous and non-leguminous species through integrated approaches. The designed studies evaluated the 10 green manure crops included five leguminous species (i.e smooth vetch hairy vetch, common vetch, lathyrus sativus, and milk vetch) and five non-leguminous species (i.e February orchid, chinese radish, forage radish, rapeseed and ryegrass) were planted. Experimental results indicated that the smooth vetch had highest P and K uptake capabilities among all leguminous species. While, rapeseed and chinese radish greatly P and K obtain among all non-leguminous treatments. Therefore various species also affected soil P and K availability and soil enzymes. Soil enzymatic activities including phosphatase (150.7%) and N-acetyl-glucosaminidase (95.4%) were elevated in lathryus sativus compared to the hairy vetch and common vetch respectively. The highest β-glucosidase (95.2%) and leucine-aminopeptidase (107.6%) activities accumulated in lathyrus sativus greater than the smooth vetch in all legumes species. In non-leguminous treatments phosphatase (500.5%), β-glucosidase (424.4%), and N-acetylglucosaminidase (256.3%) activities were improved in chinese radish as compared to the rapeseed. In constrast ryegrass was promoted greatest leucine-aminopeptidase activity by 182.7% higher than forage radish. However soil enzymes significanlty improve soil nutrient status. As a conclusion smooth vetch, rapeseed, and Chinese radish varieties have more P and K obtain capacity and forage radish could enhance soil enzyme activities. It is suggested these varieties might be a better choice in green manuring practice for improving nutrient management and soil nutrient quality in agro-ecosystems.

Routes for Potassium Ions across Mitochondrial Membranes: A Biophysical Point of View with Special Focus on the ATP-Sensitive K+ Channel

Potassium ions can cross both the outer and inner mitochondrial membranes by means of multiple routes. A few potassium-permeable ion channels exist in the outer membrane, while in the inner membrane, a multitude of different potassium-selective and potassium-permeable channels mediate K+ uptake into energized mitochondria. In contrast, potassium is exported from the matrix thanks to an H+/K+ exchanger whose molecular identity is still debated. Among the K+ channels of the inner mitochondrial membrane, the most widely studied is the ATP-dependent potassium channel, whose pharmacological activation protects cells against ischemic damage and neuronal injury. In this review, we briefly summarize and compare the different hypotheses regarding the molecular identity of this patho-physiologically relevant channel, taking into account the electrophysiological characteristics of the proposed components. In addition, we discuss the characteristics of the other channels sharing localization to both the plasma membrane and mitochondria.

Rice Potassium Transporter OsHAK8 Mediates K+ Uptake and Translocation in Response to Low K+ Stress

Potassium (K+) levels in the soil often limit plant growth and development. As a result, crop production largely relies on the heavy use of chemical fertilizers, presenting a challenging problem in sustainable agriculture. To breed crops with higher K+-use efficiency (KUE), we must learn how K+ is acquired from the soil by the root system and transported to the rest of the plant through K+ transporters. In this study, we identified the function of the rice K+ transporter OsHAK8, whose expression level is downregulated in response to low-K+ stress. When OsHAK8 was disrupted by CRISPR/Cas9-mediated mutagenesis, Oshak8 mutant plants showed stunted growth, especially under low-K+ conditions. Ion content analyses indicated that K+ uptake and root-to-shoot K+ transport were significantly impaired in Oshak8 mutants under low-K+ conditions. As the OsHAK8 gene was broadly expressed in different cell types in the roots and its protein was targeted to the plasma membrane, we propose that OsHAK8 serves as a major transporter for both uptake and root-to-shoot translocation in rice plants.

Effect of Intercropping and Fertility Levels on the Nitrogen, Phosphorus and Potash Content and Uptake by Summer Pearlmillet (Pennisetum glaucum L.) under South Gujarat Condition

A field experiment was conducted at College Agronomy Farm, N. M. College of Agriculture, Navsari Agricultural University, Navsari during summer, 2019 and 2020 comprising four intercropping treatments i.e. pearlmillet sole, pearlmillet+greengram, pearlmillet+cowpea, pearlmillet+clusterbean and three fertility levels viz., 75 % RDF, 100 % RDF and 125 % RDF. Among the different intercropping system examined, sole pearl millet (I1) accumulated significantly less content of N and P in pearl millet grain and straw as compared to intercropping with pulses treatments. Pearl millet + green gram (I2) recorded significantly higher N and P uptake by pearl millet straw than other intercropping systems. The sole pearl millet (I1) was at par with pearl millet intercropped with green gram (I2) had significantly higher K content and uptake in pearl millet grain and straw. In case of fertility levels, nitrogen and phosphorus content and uptake in pearl millet grain and straw were recorded significantly higher by application of 100 % RDF. Significantly higher N, P and K uptake by pearl millet grain and straw in pooled results were produced by treatment combination of pearl millet + green gram (I2) intercropping along with 75 % RDF (F1).

Nutrient uptake by black gram (Vigna mungo L. Hepper) as influenced by phosphorus and boron fertilization in acid Inceptisol of Meghalaya

Phosphorus and boron are required for growth and development of black gram, and play an important role in the uptake of other nutrients such as N and K. The availability of P and B is less in acid soil because of fixation and leaching losses. Therefore, a field experiment was conducted to investigate the influence of P and B on N and K uptake in black gram with four levels of phosphorus (0, 25, 50, 75 kg ha-1) and four levels of boron (0, 0.5, 1.0, 1.5 kg ha-1) comprising of 16 treatments. The trail was laid out in split plot design and replicated three times. Phosphorus was used as main plot and boron as sub-plot. Significantly highest nitrogen concentration in black gram seed was observed at P75B1.5 as 3.82%, whereas in straw, it was observed at P75B1 as 1.75%. However, significant nitrogen uptake by seed and straw was recorded as 43.85 and 39.55 kg ha-1 at P75B1.5, respectively. Similarly, significantly highest potassium concentration in seed and straw was observed at P75B1.5 as 1.13% and 1.64%. Significant highest uptake of K by seed and straw was recorded at P75B1.5 as 13.00 kg ha-1 and 36.86 kg ha-1, respectively. Therefore, 75 kg P2O5 and 1.5 kg B ha-1 is considered optimum for achieving higher nitrogen and potassium uptake by black gram in acid Inceptisol of Meghalaya.