Negative Potassium Balance Research Articles

Land use management: problems of protection of basic national wealth

The Ukrainian people, with the votes of 90.3% of those who took part in the All-Ukrainian referendum on December 1, 1991 in support of the Declaration of Independence of Ukraine, confirmed their right to land established by the Declaration of State Sovereignty of Ukraine. According to the Constitution of Ukraine, land is recognized as the main national wealth, which is under special protection of the state. The State Committee of Ukraine for Land Resources was established in 1992 of , which was directly subordinated to the Cabinet of Ministers and implemented the state policy in the field of land relations was carried out by the said central executive body.Beginning in 2000, the State Committee was transformed into the State Agency, which in 2008 was reorganized into the State Committee, then returned to its previous name, and in 2014 was transformed into the State Service of Ukraine for Geodesy, Cartography and Cadastre (State Geocadastre). For the latter body, the powers to implement state policy in the field of geospatial data infrastructure, topographic, geodetic and cartographic activities instead of implementing state policy in the field of land relations became decisive. Land relations are public relations concerning the possession, use and disposal of land. They are represented by a separate branch of law - land, which belongs to its profiling branches. This branch exists in direct connection with the basic (fundamental) branches of law that regulate primary social relations. Topographic, geodetic and cartographic activities, the sphere of national infrastructure of geospatial data do not belong to land relations. The activities of the State Agency have been directed and coordinated by five Ministries for 17 years. The implementation of state policy in the field of land relations has become a secondary task for the second body. The purpose of the studyis to analyze the process of transformation of public authorities on the formation and implementation of state land policy, its impact on land use in the state and justification of directions and ways to preserve the main national wealth. It is established that imperfection in the field of land use and protection management and the lease model of agricultural land use have deprived the economic motivation to introduce soil protection technologies in production, due to which most of the soil cover is in pre-crisis condition. A stable negative balance of humus, nitrogen, phosphorus, and potassium has been formed in agroecosystems. That was recognized as an urgent comprehensive program to neutralize challenges and threats in the environmental sphere, the National Security and Defense Council adopted a decision on this issue in March 2021.The paper focuses on the reference to state control of land use, supports the idea of improving the content of land monitoring and the procedure for its conduct, suggests ways to increase the role of state bodies in improving the land management system

БАЛАНС ЭЛЕМЕНТОВ ПИТАНИЯ В СЕВООБОРОТАХ В УСЛОВИЯХ БИОЛОГИЗИРОВАННОГО АДАПТИВНО-ЛАНДШАФТНОГО ЗЕМЛЕДЕЛИЯ

In the light of recent developments, the use of biological techniques in crop cultivation technologies needs to be expanded. The role of crop rotations with a high proportion of legume grasses, green manure crops and intermediate crops is increasing. The purpose of the research is to study soil fertility dynamics in terms of the main nutritional elements and determine their balance for the development of the adaptive landscape farming system in the North-Eastern region of the European part of Russia. Experiments were carried out on the experimental plots of the FARC of the North-East in 2002–2009. Soil – sod-podzolic middle loamy. We analyzed data of a long-term stationary experiment in four grain-fallow-grass field crop rotations. Meteorological conditions during the years of research were close to the average long-term values and favorable for crop cultivation. The introduction of low doses of fertilizers (N45P45K45 as mineral, 11.5–22.5 t/ha as green manure) increased the content of mobile phosphorus in the soil by 11–14 mg/kg (LSD05 = 9.5) in crop rotations with occupied and green manure fallows. An increase in exchangeable potassium by 15 mg/kg (LSD05 = 14.1) was noted in crop rotation with two clover fields for green manure. A positive balance of nitrogen and phosphorus was obtained in crop rotation with occupied and green manure fallows. The nitrogen balance was with a higher intake of +157.8 – +483.5 kg/ha and balance intensity – 115–140 %. The balance of phosphorus has developed at +6.0…+49.6 kg/ha. The positive balance of potassium was only in crop rotations with the introduction of green manure fertilizers and intermediate crop (+69.9…+175.8 kg/ha). The intensity of the balance of these elements was 101–118 %. In the control crop rotation with bare fallow at a minimum intake of nutrients, the negative balance of nitrogen, phosphorus and potassium was obtained; the intensity was below 100 %. Productivity of crop rotation was at the level of 4.90–5.41 thousand fodder units. According to the optimal combination of productivity and the balance of nutritional elements, crop rotation with two clover fields for green manure and an intermediate crop stood out.

Agroecological Efficiency of Organic and Mineral Fertilizers under Frozen Soil Conditions

Investigations were carried out on permafrost taiga soil in Central Yakutia in a field factorial experiment with a wide range of rates and combinations of cattle manure and mineral fertilizers. The advantage of an organo-mineral fertilizer system in N60P60K60 rates was shown against a background of 40 t of manure per hectare, which provides, under watering conditions, potato tuber yields of 18 t per hectare with starch content of 13.9%, which is 47.8% higher than in the control without fertilizer use. The yield of potatoes under the organic system with annual manure rate of 40 t per hectare was at the same level with the mineral system, but tubers contained more starch, 12.8%. It has also been established that organo-mineral and organic systems have a positive effect on the agrochemical properties of the soil, optimize its humus state and phosphate and potassium regimes. For the mineral fertilizer systems in rates of N60P60K60, the yield increment was significant, but it did not exceed 17.8% with a lower starch content in tubers, 11.5%, and a negative balance of humus, phosphorus, and potassium in the soil.

Nutrient balance in the soil and nutritive characteristics of maize silage cut at different heights

Maize harvesting for silage promotes intense use of soil nutrients. The increase in forage harvesting time can ease nutrient use and benefit the nutritional quality of the silage. However, this practice may be economically unviable due to the reduction in the volume of harvested forage. The objective of our experiment was to evaluate several agronomic parameters, such as production, plant composition, nutritional value of silage and nutrient balance in the soil by harvesting the maize plant at different silage heights: 0.20; 0.40; 0.60; 0.80 and 1.00 m above the ground. The experimental design was completely randomized, with five treatments with five repetitions. Representative plants in each plot were cut and fragmented in a forage machine. This material was homogenized and ensiled in experimental polyvinyl chloride (PVC) silos. Each 0.10 m increase at harvest provided an increase of 0.65% in the dry matter content of the forage and reduced harvest to 339 kg ha-1 of dry matter. The presence of grains in the forage increased linearly 1.24% for every 0.10 m at the time of harvest. The levels of neutral detergent fiber, acid detergent fiber and silage lignin had a linear decrease of 4.5, 2.8 and 9.6%, respectively, per each 0.10 m lift crop height. Regarding the total digestible nutrients, dry matter intake and the relative forage, these values had a linear increase of 0.5, 7.2 and 8.2%, respectively. For each 0.10 m increase in cutting height, there was a decrease in soil nutrients, namely 3.6 kg ha-1 N, 1.3 kg ha-1 P2O5, 9.5 kg ha-1 K2O, 0.9 kg ha-1 CaO and 1.2 kg ha-1 MgO. Even with the harvest at 1.00 m above the ground, nutrient recycling nutrients by necromass is not sufficient to balance the potassium balance in the soil, causing a decline of 37.69 kg ha-1 K2O. The maize harvest to 0.47 m height represented the best relationship between silage quantity and quality, being the height that presents the greatest potential for economic return, and can fund management practices and soil fertilization to prevent degradation in foraging systems, mainly to overcome the negative balance of potassium in the system.

Long–term effect of crop rotation and nutrient management on soil–plant nutrient cycling and nutrient budgeting in Indo–Gangetic plains of India

ABSTRACTIn the present investigation, the long-term effect of pulse crop inclusion in the maize-wheat rotation was assessed for the nutrient availability and soil-plant nutrient cycling under different nutrient management practices. Including pulses in the maize-wheat rotation improved soil organic carbon (SOC) and plant available macronutrients being higher in maize-wheat-mungbean rotation. Inclusion of mungbean to maize-wheat rotation enhanced the nitrogen (33.9%), phosphorus (46.4%), potassium (36.3%), and sulphur (55.5%) uptake in maize crop; likewise, alternate-year chickpea inclusion increased the uptake of these nutrients by 18.2, 19.1, 21.7, 32.1%, respectively. Inorganic fertilization maintained the positive annual balance of nitrogen, phosphorus, and zinc. By contrast, the nutrient balance under organic nutrient management was mostly negative. The magnitude of negative balance of potassium and sulphur was higher in inorganic than that of organic nutrient management. The low nutrient supply (particularly nitrogen) in organic fertilization largely inhibited the yield of cereal crops but not that of pulses. In view of this, the inclusion of pulses in the cereal-cereal systems could cause substantial improvement in soil fertility and sustainability in Indo-Gangetic plains. We infer that supply of nutrients like nitrogen and phosphorus in organic, and potassium and sulphur in recommended inorganic fertilization merit special attention.

Postoperative fluid retention after heart surgery is accompanied by a strongly positive sodium balance and a negative potassium balance.

The conventional model on the distribution of electrolyte infusions states that water will distribute proportionally over both the intracellular (ICV) and extracellular (ECV) volumes, while potassium homes to the ICV and sodium to the ECV. Therefore, total body potassium is the most accurate measure of ICV and thus potassium balances can be used to quantify changes in ICV. In cardiothoracic patients admitted to the ICU we performed complementary balance studies to measure changes in ICV and ECV. In 39 patients, fluid, sodium, potassium, and electrolyte‐free water (EFW) balances were determined to detect changes in ICV and ECV. Cumulatively over 4 days, these patients received a mean ± SE infusion of 14.0 ± 0.6 L containing 1465 ± 79 mmol sodium, 196 ± 11 mmol potassium and 2.1 ± 0.1 L EFW. This resulted in strongly positive fluid (4.0 ± 0.6 L) and sodium (814 ± 75 mmol) balances but in negative potassium (−101 ± 14 mmol) and EFW (−1.1 ± 0.2 L) balances. We subsequently compared potassium balances (528 patients) and fluid balances (117 patients) between patients who were assigned to either a 4.0 or 4.5 mmol/L blood potassium target. Although fluid balances were similar in both groups, the additionally administered potassium (76 ± 23 mmol) in the higher target group was fully excreted by the kidneys (70 ± 23 mmol). These findings indicate that even in the context of rapid and profound volume expansion neither water nor potassium moves into the ICV.

Risk factors for the development of hypokalemia in neonatal diarrheic calves.

BackgroundNeonatal diarrheic calves have a clear negative potassium balance because of intestinal losses and decreased milk intake but in the presence of acidemia, they usually show normokalemic or hyperkalemic plasma concentrations.ObjectivesTo assess whether marked hypokalemia occurs in response to the correction of acidemia and dehydration and to identify factors that are associated with this condition.AnimalsEighty‐three calves with a clinical diagnosis of neonatal diarrhea.MethodsProspective cohort study. Calves were treated according to a clinical protocol using an oral electrolyte solution and commercially available packages of 8.4% sodium bicarbonate, 0.9% saline and 40% dextrose infusion solutions.ResultsThe proportion of hypokalemic calves after 24 hours of treatment (19.3%) was twice as great as it was on admission to the hospital. Plasma K+ after 24 hours of treatment was not significantly correlated to venous blood pH values at the same time but positively correlated to venous blood pH values on admission (r = 0.51, P < .001). Base excess on admission (Odds ratio [OR] = 0.81, 95% confidence interval [CI] = 0.70–0.94), duration of diarrhea (OR = 1.37, 95% CI = 1.05–1.80), milk intake during hospitalization (OR = 0.54, 95% CI = 0.37–0.79) and plasma sodium concentrations after 24 hours (OR = 1.12, 95% CI = 1.01–1.25) were identified to be independently associated (P < .05) with a hypokalemic state after 24 hours of treatment.Conclusions and Clinical ImportanceFindings of this study suggest that marked depletion of body potassium stores is evident in diarrheic calves that suffered from marked metabolic acidosis, have a low milk intake and a long history of diarrhea.

Odběr a bilance živin při různé intenzitě využívání trvalých travních porostů

In 2003–2005 it was solved the issue about the nutrient balance in the permanent grasslands of Research Institute for Cattle Breeding Rapotín. In trial it was used these types of utilization: 1. Intensive – 4 cuts per year (1st cut up to 15th May, every next after 45 days), 2. Medium intensive – 3 cuts per year (1st cut from 16th to 31st May, every next after 60 days), 3. Low intensive – 2 cuts per year (1st cut up to 15th June, 2nd after 90 days), 4. Extensive – 2 cuts per year (1st cut from 16th to 30th June, 2nd after 90 days). There were following variants of the fertilization: A – no fertilization, B – P:K 30:60 kg.ha – 1, C – N:P:K 90:30:60 kg.ha – 1, D – N:P:K 180:30:60 kg.ha – 1. There was the considerable reaction of the permanent grassland on the nutrient application. The highest value of the coefficient of the neutral efficiency was by the fertilization N:P:K 90:30:60 kg of the pure nutrients. By the most of the variants we have noticed the negative nitrogen balance. The negative balance of the phosphorous was marked only by the unfertilized variants. All variants of the permanent grassland utilization had the negative potassium balance. The utilization had the significant influence (P0.01) to all observed indicators. The year had the significant influence too. From the point of view of the rational plant nutrition and of the environment protection from the contamination (especially from the nitrates) it appears as the most advisable the medium intensive type of the utilization with nitrogen dose: N:P:K 90:30:60.

Dynamics of the mobile forms of phosphorus and potassium in the soils of prolonged trials

During prolonged field experiments performed with various types of loamy soils, the application of phosphorus and potassium fertilizers increases the content of mobile forms of phosphorus and potassium mainly at the first rotations of field crop rotations only. Later, under positive balance, the content of mobile forms of these elements in soil does not increase and even tends to decrease due to the more intensive transformation. In the case of the negative balance of phosphorus and potassium, plants are supplied with nutrition by immobilization of fixed forms of these elements. In the sandy loam soils, these processes are less pronounced due to the lower absorption capacity of the soils to phosphorus and potassium.

Modeling the soil nutrient balance of integrated agriculture-aquaculture systems in the Mekong Delta, Vietnam

This study quantifies soil nutrient bal- ances of Integrated Agriculture-Aquaculture Systems in the Mekong Delta of Vietnam. Eleven farms were monitored to collect data on farm activities and nutrient inputs and outputs to compute these balances of the rice-based and high input fish system in O Mon district (R-HF); the rice-based and medium input fish system in Tam Binh district (R-MF); and the orchard- based and low input fish system in Cai Be district (O-LF). For the estimation, the Nutmon model has been adapted to the specific conditions in these integrated systems in Asia (Nutmon-Asia). New regression models of leaching and gaseous losses of nitrogen were applied to fields used for upland crops and paddy rice. Reference values were used for the assessment of nitrogen fixation in paddy soils, wet atmospheric deposition, and irrigation water. The results showed that farms in all three systems have nitrogen, phosphorus and potassium surpluses (84 kg N, 73 kg P, and 69 kg K ha -1 year -1 ). The O-LF system had the smallest nitrogen surplus while the smallest surplus of phosphorus and potassium was seen in the R-HF system. High surpluses of phos- phorus and potassium were found in vegetable fields, whereas a negative potassium balance was found in the rice fields of all three systems. The positive farm nutrient balances indicate that it is likely that soil fertility will be maintained although there is a risk for environmental contamination.

Hyponatremia and brain injury: absence of alterations of serum brain natriuretic peptide and vasopressin

To study any possible relation between hyponatremia following brain injury and the presence of cerebral salt-wasting syndrome (CSWS) or the syndrome of inappropriate secretion of antidiuretic hormone (SIADH), and if vasopressin, brain natriuretic peptide (BNP) and aldosterone have a role in its mechanism. Patients with brain injury admitted to the intensive care unit were included and had their BNP, aldosterone and vasopressin levels dosed on day 7. Twenty six adult patients were included in the study. Nine (34.6%) had hyponatremia and presented with a negative water balance and higher values of urinary sodium, serum potassium and diuresis than patients with normonatremia. The serum levels of BNP, aldosterone, and vasopressin were normal and no relation was observed between plasma sodium and BNP, aldosterone or vasopressin. The most likely cause of hyponatremia was CSWS and there was no correlation between BNP, aldosterone and vasopressin with serum sodium level.

THE NUTRIENTS BALANCE OF CROP ROTATION AS AN INDICATOR OF SUSTAINABLE FARMING ON ARABLE LAND

The nutrient balance of five crop rotation systems under conventional and minimal tillage with interaction of different fertilization treatments was investigated at the experimental station of Slovak Agricultural University in Nitra Dolna Malanta, during 2004-2005. The five-field crop rotation of maize (Zea mays L.) - winter wheat (Triticum aestivum L.) - spring barley (Hordeum vulgare L.) underseeded with red clover - red clover (Trifolium pratense) - common pea (Pisum sativum L.) and mustard as catch crop was used. The most serious deficit of nitrogen (- 62.2 kg.ha-1.yr-1), phosphorus (- 24.0 kg.ha-1.yr-1) and potassium (- 89.2 kg.ha-1.yr-1) was on control treatments. Deficit of nitrogen was also found-out in treatments with mineral fertilizers application. However higher deficit of nitrogen (- 25.4 kg.ha-1.yr- 1) was registered under conventional tillage. In treatment fertilized with mineral fertilizers together with by - product of pre - crop incorporation into soil (PZ), small balance surplus of nitrogen (8 kg.ha-1.yr-1 - B1, 11.5 kg. ha-1.yr-1 - B2, respectively) was calculated. The positive balance of phosphorus achieved in treatments with into soil incorporated by - products of pre - crops (in both systems of soil cultivation amounting value of 3.9 kg.ha-1.yr-1) can contribute to good supply of phosphorous in soil. The negative balance of potassium fluctuating from - 89.2 kg.ha-1.yr-1 (control treatment) to - 22 kg.ha-1.yr-1 (PZ) is acceptable owing to high content of available potassium in soil of experimental stand.

Effects of uremia and inflammation on growth hormone resistance in patients with chronic kidney diseases

Resistance to the anabolic action of growth hormone may contribute to the loss of strength and muscle mass in adult patients with chronic kidney disease. We tested this hypothesis by infusing growth hormone in patients to levels necessary to saturate hormone receptors. This led to a significant decrease of plasma potassium and amino acid levels in control and hyperkalemic patients with chronic kidney disease. These effects were completely or partially blunted in patients with elevated C-reactive protein levels. In forearm perfusion studies, growth hormone caused a further decrease in the negative potassium and protein balance of hemodialysis patients without inflammation but no effect was seen in patients with inflammation. Only IL-6 levels and age were found to be independent correlates in these growth hormone-induced variations in plasma potassium and blood amino acids. This shows that although a resistance to pharmacologic doses of growth hormone is not a general feature of patients with chronic kidney disease, there is a subgroup characterized by blunted growth hormone action. Our results support the hypothesis that uremia with inflammation, but not uremia per se, inhibits downstream growth hormone signaling contributing to muscle atrophy.

A comparison of the effects of milk and a carbohydrate-electrolyte drink on the restoration of fluid balance and exercise capacity in a hot, humid environment

Following a 2.0 +/- 0.1% body mass loss induced by intermittent exercise in the heat, seven male volunteers ingested either a carbohydrate-electrolyte solution (CE) or skimmed milk (M) in a volume equal to 150% of body mass loss. At the end of the 3 h recovery period, subjects were essentially in positive fluid balance on trial M (191 +/- 162 mL), and euhydrated on trial CE (-135 +/- 392 mL) despite being in negative sodium balance on both trials and negative potassium balance on trial CE. This difference of 326 +/- 354 mL or 0.4% body mass approached significance (P = 0.051). Subjects ingested 137 +/- 15 and 113 +/- 12 g of CHO during the CE and M trials, respectively, as well as 75 +/- 8 g of protein during the M trial. At the end of the 3 h recovery period, an exercise capacity test was completed at 61% VO(2peak) in warm (35.3 +/- 0.5 degrees C), humid (63 +/- 2%) conditions. HR (P = 0.020) and rectal temperature (P = 0.045) were higher on trial M, but no difference in exercise time to exhaustion was observed between trials (39.6 +/- 7.3 min vs. 39.7 +/- 8.1 min on trials CE and M, respectively). The results of the present study suggest that milk can be an effective post-exercise rehydration drink, with subjects remaining in net positive fluid balance throughout the recovery period. Despite the effect on fluid retention, exercise capacity was not different between skimmed milk and a commercially available carbohydrate-electrolyte drink 4 h following exercise/heat-induced body mass loss.

Métabolisme du potassium chez le prématuré

During the first days of life, hyperkalemia can affect 30 to 60% of very low birth weight infants free of acute renal insufficiency (i.e. nonoliguric hyperkalemia). The place of the kidney in the regulation of the potassium homeostasis of VLBW remains badly specified. Objective To evaluate the rate and the mechanisms of hyperkalemia in infants born at less than 32 weeks' gestation. Methods A prospective study was conducted in 33 preterm infants (BW = 1289 ± 382 g; GA = 28.8 ± 1.7 weeks). Fifteen consecutive 8-hour urine collections were performed for each infant from the 8th hour of life (495 periods). A plasma sample was obtained at the end of each urine collection. Sodium, potassium and creatinine were measured in urine and blood samples as often as possible. Results Plasma potassium concentrations varied significantly over the 15 successive periods with an initial value (P1) of 4.55 ± 0.80 mmol/l, a peak on P3 (4.94 ± 0.81 mmol/l) and the lowest value on P13 (3.88 ± 0.42 mmol/l). Hyperkalemia (plasma potassium > 6.0 mmol/l) was observed in 4 infants (12%) and in 1.2% of the periods. The cumulative potassium balance (output-input) was negative over the first 7 periods (–1.97 mmol/kg), and afterwards became positive (from P8 to P15: + 1.57 mmol/kg). Over the first 3 days, plasma potassium concentrations were positively correlated ( p < 0.01) with urinary excretion of potassium, clearance of potassium, fractional excretion of potassium, and negatively with endogenous creatinine clearance. Conclusion In the first days of life, very low birth weight infants present an increase in kalemia associated with a negative potassium balance indicating a intracellular to extracellular potassium shift rather than a lower renal potassium excretion.

Effect of Continuous use of Sodic Irrigation Water with and without Gypsum, Farmyard manure, Pressmud and Fertilizer on Soil Properties and Yields of Rice and Wheat in a Long term Experiment

A long term field experiment was conducted for 8 years during 1994–2001 to evaluate the effect of N, P, K and Zn fertilizer use alone and in combination with gypsum, farmyard manure (FYM) and pressmud on changes in soil properties and yields of rice and wheat under continuous use of sodic irrigation water (residual sodium carbonate (RSC) 8.5 meq l−1, and sodium adsorption ratio (SAR) 8.8 (m mol/l)1/2 at Bhaini Majra experimental farm of Central Soil Salinity Research Institute, Karnal, India. Continuous use of fertilizer N alone (120 kg ha−1) or in combination with P and K significantly improved rice and wheat yields over control (no fertilizer). Phosphorus applied at the rate of 26 kg P ha−1 each to rice and wheat significantly improved the yields and led to a considerable build up in available soil P. When N alone was applied, available soil P and K declined from the initial level of 14.8 and 275 kg ha−1 to 8.5 and 250 kg ha−1 respectively. Potassium applied at a rate of 42 kg K ha−1 to both crops had no effect on yields. Response of rice to Zinc application occurred since 1997 when DTPA extractable Zn declined to 1.48 kg ha−1 from the initial level of 1.99 kg ha−1. Farmyard manure 10 Mg ha−1, gypsum 5 Mg ha−1 and pressmud 10 Mg ha−1 along with NPK fertilizer use significantly enhanced yields over NPK treatment alone. Continuous cropping with sodic water and inorganic fertilizer use for 8 years slightly decreased the soil pHe and SAR from the initial value of 8.6 and 29.0 to 8.50 and 18.7 respectively. However, treatments involving the use of gypsum, FYM and pressmud significantly decreased the soil pH and SAR over inorganic fertilizer treatments and control. Nitrogen, phosphorus and zinc uptake were far less than additions made by fertilizer. The actual soil N balance was much lower than the expected balance thereby indicating large losses of N from the soil. There was a negative potassium balance due to greater removal by the crops when compared to K additions. The results suggest that either gypsum or FYM/pressmud along with recommended dose of fertilizers must be used to sustain the productivity of rice – wheat system in areas having sodic ground water for irrigation.

Effect of integrated nutrient management and crop diversification on productivity and nutrient balance sheet of rice-based cropping systems

A field study conducted for three crop years (June – July) from 1995 – 96 to 1997 – 98 at the Indian Agricultural Research Institute, New Delhi involving five rice-based cropping systems and six nutrient combinations indicated that rice – wheat – mungbean (RWM), rice – potato – mungbean (RPM), rice – rapeseed – mungbean (RRsM) and rice – clover (RC) cropping systems gave 0.7 – 1.0, 3.2 – 5.9, 0.2 – 2.2 and 1.5 – 3.6 t ha−1 yr−1, respectively, higher productivity and removed 7.9 – 22.6, 38.0 – 64.5, 53.0 – 61.8 and 51.4 – 66.1 kg ha−1 yr−1, respectively, more nitrogen, 2.3 – 7.1, 14.5 – 22.8, 3.8 – 7.2 and 17.3 – 21.7 kg ha−1 yr−1, respectively, more phosphorus and 1.6 – 11.4, 15.3 – 42.3, 8.2 – 22.7 and 40.8 – 57.8 kg ha−1 yr−1, respectively, more potassium than the rice – wheat (RW) cropping system which led to a net balance of + 151, + 58, − 153 and − 167 kg ha−1 of nitrogen, + 13, − 27, − 8 and − 59 kg ha−1 of phosphorus and − 549, − 551, − 558 and − 691 kg ha−1 of potassium after three cycles of RWM, RPM, RRsM and RC cropping systems, respectively against a net balance of + 201, + 26 and − 533 kg ha−1 of N, P and K, respectively in the RW cropping system. Application of FYM along with NPK in these cropping systems changed the negative balance of nitrogen and phosphorus into positive balance and reduced the negative balance of potassium by 151 – 378 kg ha−1. Application of P and K fertilizers along with nitrogen also helped in arresting the negative balance of P and K under different rice based cropping systems. These results thus indicate that balanced use of NPK and FYM plays a major role for sustaining the productivity of a cropping system.

Effects of non-flooded mulching cultivation on crop yield, nutrient uptake and nutrient balance in rice–wheat cropping systems

A field experiment on a sandy loam was conducted to evaluate the effects of non-flooded mulching cultivation on the productivity, nutrient uptake and nutrient balance in rice–wheat (R–W) cropping systems in Chengdu flood plain, southwest China over a 3-year period. Plastic film mulching (PM) resulted in 12% higher average yield of rice while wheat straw mulching (SM) led to 14% lower average yield of rice compared with lowland rice under traditional flooding (TF). Biomass accumulation and nutrient uptake followed similar trends to grain yield. Changes in soil temperature in relation to root growth and nutrient uptake were likely to be the major factor responsible for the changes in rice yields under non-flooded mulching cultivation. Compared with TF, PM of preceding rice did not affect the grain yield of wheat, whereas SM of preceding rice resulted in comparable grain yields of wheat at a lower N rate (60 kg N ha −1) in the wheat season. The system productivity (total yield of rice+wheat) in PM was similar to that of TF and higher than that of SM. The yield decline in rice, however, could be partly compensated by the yield increase in wheat following rice, particularly at lower N rates. Apparent nutrient budgets showed positive nitrogen (N) and phosphorus (P) balances but negative potassium (K) balance in the TF and non-flooded mulching R–W systems. Compared with TF, PM led to lower NPK balance due to more nutrient removal by crops while SM led to greater NPK balance due to more nutrient inputs from straw but less nutrient removal by crops. After 3 years soil organic carbon (OC) and total nitrogen (TN) were not significantly altered by PM and SM but soil Olsen-P (AP) and exchangeable K (EK) were significantly increased by SM compared with TF. The changes in soil properties under non-flooded mulching cultivation initially reflected the nutrient balances in R–W systems. In conclusion, non-flooded mulching cultivation as PM and SM could be applied to R–W systems in southwest China but nutrient (especially N) management should be optimized in the two systems.

Nutrient balances—a guide to improving sorghum- and groundnut-based dryland cropping systems in semi-arid tropical India

Information on soil–plant nutrient balance in India and elsewhere is scarce and mostly generalized. A review of earlier studies on nutrient balances was done to assess their relevance for researchers, policy makers, and farmers’ understanding, to manage soil fertility for sustainable crop productivity. An on-farm nutrient balance study during 1995/1996 and 1996/1997 was designed to understand nutrient balances resulting from farmers’ practices in semi-arid tropical regions of India. This diagnostic study targeted sorghum-based cropping systems and groundnut-based cropping systems in low rainfall areas of the Indian SAT. Selection of farmers for this study was done through a systematic survey and analyses of factors effecting farmers’ decision making for nutrient inputs. Intensive plot-specific nutrient input and output measurements were carried out on 53 farmers’ fields for sorghum-based systems and 45 farmers’ fields for groundnut-based system in this study. Topsoil mineral nitrogen (N) content observed in 2 years at the beginning of the crop season in two locations of Andhra Pradesh, India, was surprisingly high and exchangeable potassium (K) contents also indicated sufficient supply in most fields. Available phosphorus (P) in the majority of fields in both locations was around threshold levels, and just sufficient for most crops. The nutrient balance in sorghum-based systems indicates a moderate to higher negative balance of potassium leading to soil mining for potassium supply in these systems. Nitrogen and P balances were generally positive. Although the groundnut-based system accumulated 53% of its N requirements through BNF, negative balances of N and K were observed mainly due to low applications of these nutrients. Application of K along with options for improving BNF of groundnut are suggested. Better nodulating groundnut cultivars and efficient rhizobium strains need to be introduced. High positive balances were observed in the systems whenever commercial crops like castor and cotton were sown in the rotation. This indicates farmers’ preferences for applying excess quantities of FYM to commercially important crops even in dryland farming systems. The replenishment costs of mined nutrients annually in different cropping systems were calculated based on current market prices of inorganic fertilizers.

Diversification of rice (Oryza sativa)wheat (Triticum aestivum) cropping system for sustainable production in south Bihar alluvial plains

A field experiment was conducted during 200910 to 201112 at Sabour, Bhagalpur, Bihar to diversify the ex- isting rice ( Oryza sativa L.)wheat [ Triticum aestivum (L.) emend. Fiori &amp; Paol.] cropping system. Among the 12 rice-based cropping systems tested, scented ricepotato ( Solanum tuberosum L.) + radish ( Raphanus sativus L.)onion ( Allium cepa L.) + maize ( Zea mays L.) relay cropping gave the highest mean rice-equivalent yield (28.10 t/ha/year) and net returns ( 1,14,700/ha/year), followed by hybrid ricemaize + potatosorghum [ Sorghum bicolour (L.) Moench] + cowpea [ Vigna unguiculata (L.) Walp.] both grown for fodder (24.2 t/ha/year and 1,12,200/ha/year) and hybrid ricegarlic ( Allium sativum L.) + coriander ( Coriandrum sativum L.)maize for grain purpose + cowpea in-situ incorporation (22.60 t/ha/year and 1,11,600/ha/day). However, the benefit: cost ratio was the highest (1.39) in long-duration ricewheatmungbean [ Vigna radiata (L.) Wilczek] both sown by zero till, which was at par with scented ricewheat + fenugreek ( Trigonella foenum-graecum L.)mungbean grown for grain + residue incorporation (1.37). Scented ricepotato + radishonion + maize relay cropping required higher energy inputs (69.35 MJ 103/ha), whereas energy-use efficiency was the maximum (5.0) in ricemaize (ZT)clusterbean [ Cyamopsis tetragonoloba (L.) Taub.] (fodder). Hybrid ricemaize + potatosorghum + cowpea showed the high- est energy output (287.01 MJ 103/ha) and water-use efficiency (36.6 kg rice-equivalent yield/ha-mm). This crop- ping system removed the maximum quantity of N (448.4 kg/ha), P (130 kg/ha) and K (457.2 kg/ha) which resulted in maximum negative balance of phosphorus (32.8 kg/ha) and potassium (320.2 kg/ha). Potassium was negative in all the cropping systems, indicating that K was the most removable nutrient by the crops, which results in mining of soil K and thus calls for adequate fertilization.