<div>Background:&nbsp;Weeds are the major biological constraint in okra due to its slow initial growth and wider row spacing. Due to severe crop weed competition, weeds removed considerable amount of nutrients from the soil. Competition exists between the crop and weed for nutrients results in nutrient deficiencies in crop. Hence the present experiment is formulated to assess the effect of stale seedbed, mulching and mechanical weeding on nutrient availability, nutrient uptake by crop and weed in okra. 
 
Methods: Experiment was conducted at Coconut Research Station, Balaramapuram, Thiruvananthapuram, Kerala during Rabi 2020-21. Design adopted for the study was RBD with two factors. The first factor was seedbed preparation (S) and the second factor was weed management (W). Stale seedbed (S1) and normal seedbed (S2) were the two different seedbed preparation methods and dried banana leaf mulch @10 t ha-1 alone (W1), dried banana leaf mulch @10 t ha-1 fb wheel hoe weeding at 30 and 45 DAS (W2), dried banana leaf mulch @10 t ha-1 fb hand weeding at 30 and 45 DAS (W3), wheel hoe weeding at 15, 30 and 45 DAS (W4), hand weeding at 15, 30 and 45 DAS (W5) and weedy check (W6) were the six different weed management options tried. Soil samples were collected after the harvest of the crop to determine the nutrient availability. Weed samples at 30 and 60 DAS and plant samples at harvest were analyzed to determine the NPK content and respective uptake of nutrients were calculated by multiplying the nutrient content with DMP. 
 
Result: Stale seedbed significantly enhanced the dry matter production and nutrient uptake by okra at harvest and lowered the nutrient removal by weeds at 30 and 60 DAS. Compared to non-stale, stale seedbed recorded significantly higher fruit yield. Among the weed management, wheel hoe weeding at 15, 30 and 45 DAS, recorded the lowest total weed dry weight at 30 and 60 DAS and resulted in the highest NPK uptake by crop and fruit yield. Uncontrolled weed growth resulted in a loss of 81.33, 18.16 and 50.84 kg N:P:K ha-1&nbsp;at 30 DAS and 102.09, 57.90 and 55.31 kg N:P:K ha-1 at 60 DAS, respectively. Nutrient removal by weeds was the lowest in wheel hoe weeding at 15, 30 and 45 DAS and the highest in weedy check. It could be concluded that, wheel hoe weeding at 15, 30 and 45 DAS was the best option for the management of weeds, higher nutrient availability and uptake and yield in okra.</div>

Nutrient Availability and Nutrient Uptake by Crop and Weed as Influenced by Stale Seedbed, Mulching and Mechanical Weeding in Okra

Background: The field experiment was conducted at the Anbil Dharmalingam Agricultural College and Research Institute, Tiruchirappalli, Tamil Nadu during rabi, 2022-2023 to study the influence of spacing and weed management practices on growth characters, nutrient removal by weeds and nutrient uptake of direct seeded rice (DSR).&nbsp; 
 
Methods: The field experiment was laid out in split plot design with three replications. The main plots were spacing of 20 &times; 15 cm, 20 &times; 20 cm and 25 &times; 25 cm. Sub plots were assigned with weed management practices viz., pyrazosulfuron ethyl 10% WP at 20 g a.i ha-1 on 3 DAS as PE + bispyribac sodium 10% SC at 25 g a.i ha-1 on 20 DAS as PoE, Pyrazosulfuron ethyl 10% WP at 20 g&nbsp; a.i ha-1 on&nbsp; 3 DAS as PE + Cono weeding on 20 DAS + hand weeding (HW) on 40 DAS, Pyrazosulfuron ethyl 10% WP at 20 g a.i ha-1 on 3 DAS as PE + Cono weeding on 20 DAS and 40 DAS, Pyrazosulfuron ethyl 10% WP at 20 g a.i ha-1 on 3 DAS as PE + Bispyribac sodium 10% SC at 25 g a.i ha-1 on 20 DAS as PoE + Cono weeding on 40 DAS, Pyrazosulfuron ethyl 10% WP at 20 g a.i ha-1 on 3 DAS as PE + Bispyribac sodium 10% SC at 25 g a.i ha-1 on 20 DAS as PoE + Hand weeding on 40 DAS, Hand weeding at 20 and 40 DAS and unweeded control.&nbsp; 
 
Result: The results indicated that the highest growth attributes, higher nutrient uptake of nitrogen, phosphorous and potassium under DSR and were significantly improved by spacing 20 &times; 20 cm along with pyrazosulfuron ethyl 10% WP at 20 g a.i&nbsp; ha-1 on 3 DAS as PE + Bispyribac sodium 10% SC at 25 g a.i ha-1 on 20 DAS as PoE + Cono weeding on 40 DAS. This was on par with pyrazosulfuron ethyl 10% WP at 20 g a.i ha-1 on 3 DAS as PE + Bispyribac sodium 10% SC at 25 g&nbsp; a.i ha-1 on 20 DAS as PoE + Hand weeding on 40 DAS and hand weeding on 20 and 40 DAS. Similarly lower nutrient removal by weeds were registered under 20 &times; 15 cm spacing along with pyrazosulfuron ethyl 10% WP at 20 g a.i ha-1 on 3 DAS as PE + Bispyribac sodium 10% SC at 25 g a.i ha-1 on 20 DAS as PoE + cono weeding on 40 DAS. The interaction of spacing 20 &times; 20 cm and pyrazosulfuron ethyl 10% WP at 20 g a.i ha-1 on 3 DAS&nbsp; as PE + Bispyribac sodium 10% SC at 25 g a.i ha-1 on 20 DAS as PoE + Cono weeding on 40 DAS significantly increased the growth attributes such as plant height, dry matter production and total numbers of tillers and significantly lowered the nutrient removal by weeds.&nbsp;

Influence of Spacing and Weed Management Practices on the Growth Characters, Nutrient Removal of Weeds and Nutrient Uptake of Direct Seeded Rice

<div>Background: Maize (Zea mays L.) is the most versatile and emerging food crop of global importance. Weeds are ubiquitous but their presence in wide spaced and initially slow growing crop like maize acts as an obstacle for plentiful harvest. Nutrient uptake by weeds during the first thirty days of maize growth was 59 kg N, 10 kg P2O5 and 59 kg K2O per ha, which was 7-10 times higher than the nutrient uptake by maize. 
 
Methods: The present field experiment was conducted during Rabi, 2018-19 under irrigated conditions at wetland farm of S.V. Agricultural College, Tirupati andhra Pradesh, with ten treatments and three replications in a randomized block design. 
 
Result: Lower density and dry weight of weeds with higher weed control efficiency, lower nutrient uptake by weeds and higher nutrient up take by maize at 80 DAS, kernel and stover yield was recorded with hand weeding twice at 15 and 30 DAS, which was statistically at par with atrazine 1.0 kg ha-1 as PE fb topramezone 30 g ha-1 or tembotrione 120 g ha-1 as PoE or atrazine 1.0 kg ha-1 as PE fb HW at 30 DAS, while these were lowest with weedy check. Higher benefit cost ratio of maize was noticed with both atrazine 1.0 kg ha-1 as PE fb topramezone 30 g ha-1 as PoE (T3), which was in parity with atrazine 1.0 kg ha-1 as PE fb tembotrione 120 g ha-1 as PoE (T2) and hand weeding twice at 15 and 30 DAS (T9). From the present study it may be concluded that atrazine 1.0 kg ha-1 as PE fb topramezone 30 g ha-1 or tembotrione 120 g ha-1 as PoE were considered to be the most effective and economic weed management practices to increase the productivity of Rabi maize at times of labour scarcity.</div>

<div>Weed Dynamics and Nutrient Uptake of Maize as Influenced by Different Weed Management Practices</div>

Background: Presently, labour force is diminishing and becoming costlier. In agriculture management of weeds in cropped field has become a real challenge to the farmers, since weeds are affecting the crop yields due to competition for growth resources. Intercropping of leguminous crops and application of pre-emergence herbicides offers an ample scope for weed control. 
Methods: The present study was conducted at University of Agricultural Sciences, Bengaluru during 2016 and 2017 on red sandy loam soil and the experiment was laid out in randomized complete block design (RCBD) with factorial concept and replicated thrice. There were 15 treatment combinations involving three intercrops and five weed management treatments. 
Result: The results revealed that intercropping of maize with cowpea has recorded significantly higher grain yield (5842 kg/ha), stover yield (7035 kg/ha) and total nutrients uptake (99.53, 27.37, 96.95 kg/ha NPK, respectively). Among the chemical weed management practices, pre-emergence application of pendimethalin 30% EC @ 1.50 kg a.i./ha has recorded significantly higher grain (6589 kg/ha), stover yield (8033 kg/ha), maize equivalent yield (8860 kg/ha), total nutrients uptake (112.81, 31.05, 109.88 kg/ha NPK, respectively) and B:C ratio (3.35) compared to other weed management practices.

Comparative Efficacy of Leguminous Intercrops and Weed Management Practices on Nutrient Uptake, Productivity and Profitability of Maize based Intercropping System

<div style="text-align: justify;">Field investigations were conducted during 2015 and 2016 kharif seasons at the experimental farm of ICAR, Nagaland Centre, Medziphema to study weed growth and nutrient uptake in organically managed rice and maize as affected by N management and live mulching with cowpea. The experiment was laid out in factorial RBD with two kharif crops viz., rice (C1) and maize (C2), two organic N management viz., vermicompost @ 2 t/ha (N1) and vermicompost @ 2.7 t/ha (N2) and two mulches viz., control (No mulching) (L1) and live mulching with cowpea (L2). The dominant weed species observed were Cynodon dactylon, Digitaria setigera, Ageratum conyzoides, Amaranthus viridis, Cyperus iria and Cyperus rotundus. Weed density, dry weight and NPK uptake was found to be significantly lower in maize compared to rice during both years. Weed growth and NPK uptake was also found to be significantly higher with application of vermicompost @ 2.7 t/ha (N2) compared to 2 t/ha (N1) whereas, significantly lower weed growth as well as NPK uptake was also recorded with cowpea live mulch (L2) as compared to no mulching (L1). Cowpea live mulch (L2) with application of vermicompost @ 2 t/ha (N1) was found to record significantly lower NPK uptake by weeds in both crops. Yield and yield attributes of rice and maize were observed to be higher under cowpea live mulch with application of vermicompost @ 2.7 t/ha (N2).</div>

Weed growth and nutrient uptake in organically managed rice and maize as affected by nitrogen management and live mulching with cowpea

Background: The cropping systems in any agro-ecological zone in the globe are driven by a number of critical issues, including rising food demands, the depletion of land and the degradation of land resources. The goal of traditional cropping methods has been to maximise crop yields. Cropping systems that take into account the new social, economic and ecological or environmental considerations are urgently needed nowadays. Due to their adaptability to diverse cropping patterns and capacity to fix nitrogen, legumes can offer prospects for continuous increases in productivity. Legume-based crop rotations help to maintain of organic matter, increase of soil nitrogen, nutrient balance, maintenance of soil physical qualities and disruption of soil-borne disease cycles. Conservation tillage is centered on minimum tillage, permanent raised beds, zero tillage with low soil disturbance and the preservation of protective plant cover or plant residues on the soil surface to prevent soil losses, stimulate microbial population and retain moisture and nutrients.&nbsp; 
 
Methods: Field experiment were conducted during 2019-20 and 2020-21 at the Main Research Station (MRS), GKVK, University of Agricultural Sciences, Bangalore On sandy loam soil&nbsp; to study the performance of Weed management in maize-based cropping system in conservation agriculture. The experiment was laid out under split plot design with five main plots on different tillage treatments i.e., Conventional tillage, Zero Tillage, Minimum Tillage, Minimum Tillage and Permanent raised bed and three sub plots of different weed management practices i.e., Chemical weed management practices, Integrated weed management practices and Unweeded Control replicated thrice. 
 
Result: Among tillage practices, permanent raised bed recorded the least total weed density and weed dry weight at harvest when compared to other tillage practices and also high seed yield, haulm yield and B: C ratio due to less weed&nbsp; infestation, good root growth, adequate aeration and nutrient availability compared to other tillage practices. Permanent raised beds had significantly higher nitrogen, phosphorus and potassium uptake than zero tillage. Among weed, management practices, Integrated weed management (Pendimethalin-750 g/ha (PE) + Hand weeding at 30 DAS) recorded the least total weed density and weed dry weight at harvest compared to unweeded treatment and also high seed yield, haulm yield and B: C ratio due to less weed infestation, compared to unweeded treatment. Integrated weed management resulted in significantly higher nitrogen, phosphorus and potassium uptake compared to unweeded (control).

Tillage and Weed Management on Yield and Nutrient Uptake of Greengram under Maize-greengram Cropping System in Conservation Agriculture

Background: Urdbean (Vigna mungo L.) yields are heavily impacted by weed infestations, which compete aggressively for space, light, water and soil nutrients. To address this issue, a field study was executed to determine the impact of integrating herbicidal and mechanical weed management on weed parameters, crop growth, nutrient uptake through weeds and final grain output. 
 
Methods: During the Kharif season (2023), a field trial was executed in Kota, Rajasthan, to investigate how distinct mechanical and chemical weed control strategies alter weed proliferation, crop-weed nutrient competition and final urdbean yields. Utilizing a randomized block design with three replications, the study compared ten separate treatments consisting of individual and combination weed management techniques. 
 
Result: The experimental field was characterized by a diverse infestation of both narrow-leaved (grassy) and broad-leaved weed flora. Compared to the unweeded control plots, all evaluated weed management strategies significantly curtailed weed density and dry biomass accumulation. Concurrently, these interventions lowered weed-induced nutrient exhaustion across all growth stages of the crop. Among the tested regimes, manual weeding executed twice (at 20 and 40 DAS) demonstrated the highest efficacy in suppressing weed counts and dry matter, consequently minimizing the depletion of primary soil nutrients by weeds. Furthermore, this dual hand-weeding practice optimized weed control efficiency, culminating in significantly superior grain and stover yields. However, the performance of Fomesafen 11.1% + fluzaifop-p butyl 11.1% SL (Ready mix) @ 220 g a.i./ha remained statistically at par with this treatment. 
&nbsp;

Effect of Herbicidal and Mechanical Weed Management on Weed Dynamics, Nutrient Depletion by Weeds, Growth and Yield of Urdbean [Vigna mungo (L.) Hepper]

<div>Background: A field experiment was conducted during two consecutive Rabi (winter) seasons of 2016-17 and 2017-18 at Sardarkrushinagar Dantiwada Agricultural University, Sardarkrushinagar, Gujarat, India to assess the impact of wheat varieties and integrated nutrient management practices on nutrient content and uptake and soil nutrient status. The soil of the experimental plot was loamy sand in texture, low in organic carbon (0.24%), available nitrogen (159 kg/ha) and Zn (0.41 mg/kg), medium in available phosphorus (38.90 kg/ha) and high in available potash (287 kg/ha). 
 
Methods: Experiment was laid out in a Factorial RBD with three replications, consist of four wheat varieties viz. GW 273, GW 322, GW 451 and GW 496 and six integrated nutrient management (INM) practices viz. control, 100% RDF, 100% RDF + Azotobacter + PSB, 75% RDF + Azotobacter + PSB, 75% RDF + Azotobacter + PSB + ZnSO4 and 50% RDF + 25% N through FYM + Azotobacter + PSB + ZnSO4.&nbsp; 
 
Result: The pooled results indicated that uptake of nitrogen, phosphorus and potassium by grain and straw, grain yield and straw yield were found higher with wheat variety GW 451 as compared to other wheat varieties. Nutrient content in grain and straw was not significantly affected by different wheat varieties. Among nutrient management practices, nitrogen, phosphorus and potassium content, uptake, grain yield and straw of wheat were significantly higher under application of 100% RDF + Azotobacter + PSB. Further, result revealed that different wheat varieties did not bring any significant variation in available nitrogen, phosphorus, potassium, zinc and organic carbon content in soil. Moreover, highest available nitrogen and phosphorus in soil was recorded with the application of 100% RDF + Azotobacter + PSB. However, significantly higher organic carbon and zinc content in soil was observed under 50% RDF + 25% N through FYM + Azotobacter + PSB +ZnSO4.</div>

Effect of Wheat Varieties and Integrated Nutrient Management Practices on Nutrient Content, Uptake and Soil Nutrient Status

<div style="text-align: justify;">&nbsp;A field experiment on soybean was conducted at the regional research farm of the Punjab Agricultural University, Naraingarh (Distt. Fateh Garh Sahib) for three years under irrigated conditions for productivity enhancement through integrated nutrient and other agronomic interventions. There were twelve treatments comprising different levels of N, P, K, FYM and agronomic management practices. The results revealed that soybean significantly responded to the application of N, P, K and FYM. &nbsp;Maximum yield was recorded in the treatment where FYM was applied with NPK and resulted in an increase of 10.8 per cent over NPK alone. Application of additional 30 kg N ha-1 at pre-flowering or at pod initiation did not significantly enhance the yield over the basal dose of NP applied at sowing. &nbsp;Application of 4 tonnes wheat straw mulch + 30 kg N +60 kg P2O5 and 30 kg N + 60 kg P2O5 ha-1 &nbsp;showed similar effect on seed yield of soybean. No statistical difference in soybean yield was observed in the conventional flat and bed sowing treatments. Pre-emergence application of pendimethaline @ 1.5 l ha-1 along with one hand weeding at 40 days after sowing (DAS) and two hand weeding at 20 and 40 DAS were equally effective for weed control and in influencing the soybean yield. The application of N, P, K and FYM, in different treatments, treatment with Bradyrhizobium japonicum and sowing on beds all significantly improved the N, P and K uptake by soybean over control. &nbsp; Application of FYM to soybean resulted in maximum nutrient uptake by soybean. &nbsp;After three years a significant improvement in soil organic carbon, available N, P and K was observed in all treatments over control.&nbsp;</div>

Effect of integrated nutrient and agronomic management on growth, productivity, nutrient uptake and soil residual fertility status of soybean&nbsp;

<div>Background: The excessive usage of chemical fertilizers and the negligence on soil health regarding the conservation and use of organic sources of nutrients have not only caused the exhaustion of soil nutrient reserves but also resulted in soil health problems which is not conducive to achieving consistent increase in agricultural production. The beneficial influence of organic matter on the physical, chemical and biological properties of the soil is well known, the full appreciation of the same remains which is unfortunately ignored in modern agriculture. The regular recycling of organic wastes in the soil is the most efficient method of maintaining optimum nutrient reserves of soil and nutrient uptake by the plant. The Present Study was conducted to evaluate the nutrient status of soil under integrated usage of organic and inorganic sources. 
 
Methods: A field experiment entitled &ldquo;Nutrient Management Interventions in Rice-Ragi Sequence&rdquo; was conducted during kharif and rabi seasons of 2017-18 and 2018-19 on sandy loam soil of the Agricultural College Farm, Bapatla. The seven treatments consisted of T1: 100% RDF (100-60-40 kg N-P-K ha-1); T2: 100% RDF + Soil application of ZnSO4 @ 50 kg ha-1; T3: 125% RDF+Soil application of ZnSO4 @ 50 kg ha-1; T4: 75% RDF + Poultrymanure&nbsp; @ 0.82 t ha-1 + Soil application of ZnSO4 50 kg ha-1; T5: 75% RDF + FYM @ 5.0 t ha-1 + Soil application of ZnSO4 @ 50 kg ha-1; T6:50% RDF + Poultrymanure @ 1.6 t ha-1 + Soil application of ZnSO4 @ 50 kg ha-1 and T7: 50% RDF + FYM @ 10 t ha-1 + Soil application of ZnSO4 @ 50 kg ha-1. The experiment was laidout in randomized block design with seven treatments and replicated thrice during kharif rice and in rabi each kharif treatment was subdivided into four sub treatments (S1: Nofertilizer, S2: 100% RDF, S3:75% RDF and S4:50% RDF) and hence, The split plot design was adopted in rabi. Total No.of plots per each replication in the rabi was 28 (7x4=28).&nbsp; 
 
Result: Nutrient content and uptake of nitrogen, phosphorus, potassium and zinc have increased significantly with the fertility levels and organics. 50% RDF + FYM @ 10 t ha-1 + ZnSO4 @ 50 kg ha-1 recorded the highest nitrogen, phosphorus, potassium and zinc contents and uptakes in grain and straw of rice. In no till rabi ragi, N, P, K, Zn and calcium content and uptake in grain and straw were found to be significantly superior with 100% RDF (S2) to the rest of the treatments in both the years and in pooled data.</div>